@AphoticLee
Sorry for the late response.
The best I can recommend is a new GPU and RAM.
Without breaking the budget, I recommend the GTX 1650 Super as it is the only thing that can suit a 500W PSU.
https://www.newegg.com/asus-geforce-gtx-1650-super-tuf-gtx1650s-o4g-gaming/p/N82E16814126358?&quicklink=true
G. Skill 16GB:
https://www.newegg.com/g-skill-16gb-240-pin-ddr3-sdram/p/N82E16820231673?&quicklink=true
As your CPU is quite old, your options are a bit limited to what you can upgrade.
If possible, I would also recommend upgrading to a better power supply - better for future capability (barring your ancient CPU/motherboard, which will need to be upgraded eventually).
https://www.newegg.com/antec-neoeco-650c-ne650c-650w/p/N82E16817371125