Question Looking to upgrade, not sure what to buy

[Apex1013]

Hi everyone, I am currently looking to upgrade my old gaming PC. I'm just looking to get a new CPU, motherboard, and power supply. I am currently using a 7 year old Dell factory tower. It has an i5-3330, so pretty much anything else would be an upgrade. I am hoping to get all the parts for 500$ or less. Any suggestions would help out a lot!

 

[vapour]

Major usage?
Living in US?
Any reusable parts? If HDD only, I will add an SSD as the HDD may be breaking down soon.
New platform usually requires DDR4 too, you may need new ram. I will suggest new Ryzen platform for best cost-effectiveness.