need a good budget pc under 800$ and can handle gaming.

I noticed a couple of things that I would recommend changing.

I noticed that you've selected the 32bit version of windows. You'll want to purchase the 64bit to take full advantage of the parts you've selected. I would recommend selecting a Z490 motherboard for the same reason. The current motherboard that you've selected does not allow for overclocking. While I wouldn't recommend overclocking with your current setup, you might want to in the future and you wouldn't want to purchase a new motherboard just to do so.

You won't need to purchase any additional thermal paste at this time, as the cooler comes with pre-applied thermal paste.

I would also recommend upgrading to 16GB of RAM as the cost difference is very small.

Lastly, I would recommend going with a 500GB or 1TB SSD instead of the 2TB HDD you've selected. If you think you'll need more room for data later, you can always add it as you need it!

I hope this info helps! Please let me know if you have any questions!