Hi.
In the motherboard manual( or manufacturer website) you should find the devices supported by your model, the kind and amount of RAM and many other useful information, the manufacturer of your mainboard is the most qualified person to tell you what you can and what you can't plug in your system.
If like you said, you are starting to learn tech stuff, one of the first things you should know is :
- The Orchestra director in your PC is a thing Called "CHIPSET", it dictates the kind of CPU, RAM, HDD...etc.
If you are really interested in technical things about computers, i suggest you to read what is behind the link.
NOTE: The doc is a little out of date but still applies. You will need ACROBAT READER to open it.
http://www.khwarzimic.org/takveen/chipset.pdf

Knowledge is the most powerful weapon.
Good luck.

Go to bois check memory configuration for frequency and size

The best way to find out the right RAM is to take out the old sticks and get the same speed/type as them.