The best way to get advice is to create a new topic, which you can do from the main page. You should put it in the "new builds and planning" section, and include a pcpartpicker.com list of what you already have. You should also list your budget and country, as well as the intended performance target of the computer.

i have 500 USD budget and want a discrete gpu with 16gb ram. I will mainly be playing Esports titles such as Rocket League and CS GO. Got any suggestions?

don't need os, peripherals or monitor, just the main rig.

So are you upgrading or just buying a new PC? Because your post says you want an upgrade but you seem like you're interested in a whole pc