Upgrading My EliteDesk for Gaming and LLM: What’s Possible?

Hey everyone! I have an EliteDesk 800 G5 Series Tower/SFF with the following specs: an i5-9500, 16GB RAM (2x8GB at 2666MHz), and a 1TB SSD. I'm looking to enhance my setup for both gaming and running a language model. I'm considering adding more RAM (maybe at a higher frequency) and a graphics card. My budget is around $500, but I'm open to spending a bit more if it makes sense. I'm a beginner gamer and will be playing on a projector, so I don't need super high FPS, but I'd love to play something like Cyberpunk 2077 with decent graphics. I also want to know if this upgrade is too ambitious for my current setup and what would give me the best value for my money. Thanks a bunch!