Linux 101 stuff. Questions are encouraged, noobs are welcome!

After more than a decade in the Windows world, I'm finally taking the step into the Linux world, specifically considering Ubuntu or Fedora. I'm looking for advice on making this transition as seamless as possible, with a focus on improving my coding experience and ensuring a smooth gaming setup.

What are the key things I should take into account for a good transition? Any must-have tools, software, or tweaks? Additionally, I'm keen on maintaining a good gaming experience – any tips for optimizing gaming performance on these distros?

Your insights, recommendations, and personal experiences would be immensely helpful as I embark on this exciting journey. Thanks in advance for your guidance!