how would I install the RAM if I buy it on like newegg
I'm looking at modules RN and they're absolutely confusing
Well you got to determine which kind of RAM your system supports
Theres 3 kinds, DDR1, DDR2, and DDR3, with DDR4 being phased in at the moment, and two form-factors - DIMM and SODIMM
DDR4 is top of the line but most contemporary computers use DDR3 or DDR2
Now, if your computer is a Laptop, you're most likely going to be using SODIMM modules, which are the smaller sticks, while regular computers mostly use DIMMs
Heres an image that sums up what the two look like

Now, once you've determined whether your RAM compatibility is DIMM or SODIMM, you'll have to look up that DDR number your computer uses, which is important because computers can only support one DDR type which is determined by the motherboard.
So once you've determined the DDR and whether its SODIMM or DIMM, then choose a frequency and I think you should be set. Someone else can tell you about frequency.
As for actually installing it, you'll have to literally open up your computer case to do it, as with the majority of hardware.
There are tutorials on youtube about how to do this, and the procedure varies between computer models but the concept is the same and is pretty easy
One thing to remember though, always use an electro-static wrist strap
Static Electricity is like a guillotine to electronics