How to Install Davinci Resolve (and Studio) on Linux [examples here have worked for my Debian distribution instances and on older system hardware and NVidia GPU.]

Description:
Davinci Resolve requires the latest NVidia's drivers to operate. Linux comes with open source drivers for Nvidia GPUs that are not supported by Davinci Resolve. You will need to not only uninstall the open source Nvidia drivers but to also blacklist Linux from reinstalling them. Then you will need to boot in console as root or superuser from sudo account to install the Nvidia drivers. Before that you want to make sure you have what is required to recompile your Linux kernel with the dev and headers. The NVidia driver installer will compile it's video driver into your Linux kernel/ Then you can run the Davinci Resolve installer after a reboot.

Caution & Consideration:
Upgrading kernel to the latest version after setup will overwrite the Nvidia drivers and render your system being stuck in a login loop trying and failing to load Xwindows (your GUI environment.) If this happens you will want to reboot and type 'E' for edit when Grub loads; then you want to add '3' to the end of the Linux header boot image argument as run level 3. This will temporarily give you console mode only so you can go ahead and recompile the latest NVidia driver for your new Linux kernel version as root or superuser. 

Also when purchasing the Studio version, I have preferred the dongle over the serial number. If for example your serial number leaks out then you risk on losing your ability to run Studio version. Using a dongle ensures you have access so long as you have your USB dongle handy for the Studio version. All things serial number abuse aside: it is more convenient to not have to enter a serial number every time you install Davinci Resolve on a system. If you go the Dongle route, save the packaging that your Davinci Resolve software came in: you will need this has it contains the serial number that you need to include in download requests for newer versions of Davinci Resolve Studio from the BlackMagic main website, download request area.

System specifications:
Make sure your system processors have at least 4 cores and with SSE4.1 support or newer. I run a 12 year old Xeon 6 core unit with 12 threads, 32gb of system memory and a 1050ti NVidia GPU with 4gb of memory; I am able to render high quality 1080p content with near real time preview off my timelines also with smooth scrubbing (including timelines embedded.) You want at least 1000 CUDAs in your GPU.

Steps [still may need some corrections; feedback is welcome]:

1. If you have a NVidia GPU, Download NVidia driver from (choose production branch):
https://www.nvidia.com/en-us/drivers/unix/

2. Download your preferred version of Davinci Resolve (or Studio if you have license or dongle) at:
[Free & Studio $$$]: https://www.blackmagicdesign.com/products/davinciresolve

3. Now that you have the proprietary packages you need downloaded, mostly everything else is done in console mode before installing Davinci Resolve. Reboot your system and when grub comes up, hit "E' to edit grub boot specifications. Navigate to where the Linux img is loaded and at the very end of that line, add a space and the number 3 for run level 3 (console mode.) This option does not save to grub so it is ideal for one time use. Hit [F-10] key to save per boot instance and boot to console.

4. Making sure you have root user as some Debian like distros such as Ubuntu do not have a root user as default.
Skip this step if you already have a root user active and know it.
sudo passwd root
[set a strong password for root]
then
su
[enter root password]

5. Make sure you are root or superuser:
su
[enter root password]

6. Install necessary kernel dev and header packages so that the NVidia installer has what it needs to recompile its driver in the system kernel.
sudo apt install linux-headers-$(uname -r) build-essential

7. Blacklist Nouveau nvidia driver:
bash -c "echo blacklist nouveau > /etc/modprobe.d/blacklist-nvidia-nouveau.conf" && bash -c "echo options nouveau modeset=0 >> /etc/modprobe.d/blacklist-nvidia-nouveau.conf"

8. Uninstall Nouveau nvidia driver:
apt purge nouveau

9. Update the kernel:
update-initramfs -u

10. Reboot back to grub pressing 'e' to edit and one last time add ' 3' to the end of where the linux img is loaded.

11. Go to where you downloaded the NVidia installer, ie where [$USER] is the user whence you downloaded the driver:
cd /home/$USER/downloads/

12. Type './NVid' then press [TAB] key to auto-complete and press [ENTER] key.

13. Let the installer run. If successful then reboot normally. Log in your system.

14. Insert USB key dongle (or have your serial number handy) and open a terminal window, go to where you downloaded Davinci Resolve and type:
DaVinci [TAB] and add '--install' and press enter. Input your sudo password when prompted during the install. [sic: I have to double check actual installer name]

How to run Davinci Resolve:
Open a run dialogue or run a terminal and enter:
/opt/resolve/bin/resolve

Handy scripts to have:

The free version of Davinci Resolve and Studio versions on Linux do not yet decode AAC audio from MP4 h264 codec files. I have a modified script I use to batch convert media files of a specific container extension to a format that Davinci Resolve likes:

Create 'bmdr' and paste code between "Start" and "End" markers below:
nano ./bmdr

************* Start ****************

#!/bin/bash

# usage: bmdr [extension]
# Hashed together by Jason Page of Page Telegram with original script from Oliyan of Telegram shared as public domain.
# This script converts using ffmpeg all files of a specific extension in
# a folder to native video format for BlackMagic's Davinci Resolve in Linux.

# Do the conversion and put converted files sub folder 'transcoded'
mkdir transcoded; for i in *.$1; do ffmpeg -i "$i" -vcodec mjpeg -q:v 2 -acodec pcm_s16be -q:a 0 -f mov "transcoded/${i%.*}.mov"; done

cd transcoded

# Remove spaces in these file names
sed 's/^/file './ /' files.txt
sed -e 's/$/'/' -i files.txt
# Clean up
rm ./files.txt

************* End ****************

You want to make this script executable and somewhere in global system path. For example:

chmod +x ./bmdr
sudo cp ./bmdr /usr/bin

Then you can run this script from anywhere within your bash shell. If you get errors related to missing components, make sure you have ffmpeg installed, ie:
sudo apt install ffmpeg