Have a go at it. If you have a complete wheel to start with it gives you the chance to take pics and make notes of where spokes go and where they have come from. Also the orders of spoke head on the outside and inside of the flanges. Start from the valve hole and start making notes with little drawings and pay attention to the number of holes between each spoke that goes in the same direction. Stuff like that combined with looking at some pics on the internet and if the wheel comes apart ok you KNOW 100% that it will go back together if you do it all right.
Don't get lost in rabbit holes of spoke tension, different spoke patterns, spoke lengths etc for your first build if you aren't to sure of things.
No. 1 rule is buy a very good spoke key that properly fits the nipples. Avoid multi keys that look like they have been pressed out of a hubcap! You might need a couple as wheels can have had spokes and nipples replaced so sizes might be a little different.
I built my first wheels a few years ago. Copied what i had taken apart first and then changed spoke patterns, bought some new spokes and that went very well, too. Even ordered the wrong length spokes for one wheel and built something alot of the internet will have to reply with dentist comments but it was and is still perfectly true and solid.
Alot of the internet is full with nonsense, hearsay, and opinion regarding wheel building. This website, i have found, is not and i think it is fair to say that 99% of regular users here will help and guide you with real world knowledge and experience. If someone is close by they might even pop round to help.