First I understand that there are way better options than what I am going to ask for but this is how I want to do it...now I cant due to lack of knowledge figure out the rest ...
Which is adequate explanation of why you are trying to do this when you shouldn't bother...but, OK, here you go:
That motherboard maxxes-out at 2GB DDR2 for system memory; so, if you're already at 2GB, you're stuck there. If not...go to the Crucial website and search-up compatible memory for that model number.
You
can upgrade to an Athlon 64 X2 6000 3.1Ghz processor.
https://www.amazon.com/AMD-Athlon-ADV6000IAA5DO-Socket-Quiet/dp/B009Z3X1MC
The GPU that you bought
is an AGP card, so it should work fine.
PSU....a cheap Antec 350W will do just fine.
https://www.amazon.com/Antec-Basiq-BP350-Power-Supply/dp/B000H9J3ZC
Dutch Uncle time....you have what you need to do what you want to do; but that machine is over 10 years-old, which puts the motherboard right at the end of the "bad capacitor plague" of a while back. You risk running into MB failure as soon as you're done with all of this.
If the MB dies on you, and there's a good chance that it will....start looking on eBay for another one.