need help upgrading my ssd on pc

Install windows, all your games on a nifty 1tb, something happens with windows poof everytrhing gone, why 256gb at most is enough, get either a seperate if you really insist on "faster" gaming or just a plain old 2tb hdd.

For the rest it's just plugging in a sata cable, not sure how much there can go wrong with it, it's not rocket science.

The best way to learn it would be to check out some videos on YouTube. Depending on which SSD drive you own be it NVMe M.2 or SATA SSD you use these words and add "install with or without installing operating system (Windows 10 mb)" or if you need to clone your existing system you search "clone system to SSD".

i will go out on a limb and say the motherboard for that cpu only supports sata III

so your system is old, you will need SATA SSD.
the new (M.2) type will not fit
screen shots from "CPUz" or similar programs will give us more details

My brother once installed a 1tb ssd, but it fucked up my computer so much

if you already have SSD and want to add a bigger one, its as easy as plugging a USB.
we will keep every thing (windows and old files) on the old one. and the new one will be extra storage.
https://www.youtube.com/watch?v=8JOxKSkkdMM

Go big or go home. Platter drives should only be used for archiving, in my opinion.

I'd slip in a 1TB SATA (since you can't use M.2 on that mobo) for your OS and a good number of your games, along with most of your other apps. No one likes loading screens (the person that does likely also enjoys slamming his nuts in a car door, and that's not you), or dealing with pop-in textures, or listening to their friends complain because you're the last one in-game every.single.match.

SATA SSDs can be had for a song and a dance nowadays, so splurge and get a good sized one, IMHO. And, should you upgrade the rest of your rig later, you can migrate that drive over to it.

Your mainboard is rather outdated since you cannot install nvme ssd which is a lot faster through pci express bus versus ssd that just uses the old sata bus. So follow Lugum's advice and buy a samsung ssd that gives for free data migration software that its very easy to use. Just plug your new ssd into a sata slot, boot your pc , istall samsung migration software and do the cloning. 256gb is usually enough but bigger is better. Just make sure that data on your current disk is not more than the capacity of the ssd you are going to choose. You cannot clone for example 251gb of data on a 250gb ssd. So calculate this if you want to do cloning.
There is also a more expensive option for you. Buy an Nvme Pcie adaptor and an nvme ssd , plug it in into your second PCI-E X16 slot, boot to bios, make your new ssd first boot option, then install windows and let your old hard drive as a second disk. Your system will be a lot faster this way. I recommend this only if you dont mind installing windows again, because in this case migration software wont work.

The first question is: what games do you play?
Like Lugum recommended, get a small Samsung / WD 256 / 500 SSD for windows. Then get a separate 1 / 2 TB SSD for games that need the speed. Mostly online games or open world (GTA V is a great example). Put the rest on a platter...why? Because balance is everything.
Don't worry about nvme