Just a few tips to help get you started(I'm assuming you have 0 clue how to hex edit so sorry if this comes off as patronizing!:
Everything in the save data is in hex, so you'll need to learn how to convert for that or just use this handy converter:
http://www.binaryhexconverter.com/decim ... -converter
The way this works is, let's say if you were looking for your money in some random game, and you had 6500, as opposed to searching for 6500, you'd look for 1964 instead as that's what 6500 is in hex.
Second thing to note is ps4 save data is in little endian meaning that everything is flipped. So when it comes to creating codes, or just basic editing in general, you have to flip it. You can read more up on this here:
https://www.hhdsoftware.com/doc/hex-edi ... order.html
Third thing to note is that some values are just flat out not editable. In more recent years games have put strict integrity checks into their games to enforce values that flat out can't be edited. These are usually find in values relating to your characters level in a rpg (Kingdom Heart 2.8 with Aqua's stat, FFXV with Noctis.') So when you go in an edit certain things, just because it didn't change, doesn't necessarily mean you're doing anything wrong, so don't get frustrated!
Another quick tip is to go install HxD which you can find here:
https://mh-nexus.de/en/hxd/
The save wizard program its self is rather unintuitive when it comes for actually searching for values (also note you can't do any actual editing in this program.)
The last thing to note is: don't get frustrated! Take your time, and try not to get overwhelmed. There's a lot of numbers inside save data so if you just start looking through it, it seems rather daunting. Just ask detailed questions and someone is surely to help you!