I was luckily able to get ahold of an 80 percent p220 frame from matrix and this would be my first time building a handgun, would also be my first sig pistol. Anything I should be aware of? trying to get either a 9mm p75 parts kit or german .45

I've used a Matrix jig to cut rails on 1911 80% frames and built 3 1911s. I am not familiar with doing the P220, but there should be some videos about using it. YouTube has been cracking down on videos showing gun making stuff, so I would also suggest looking for videos on Rumble and Odysee as well. It's possible that YouTube left the older videos up, but some of the folks who made them a few years ago have to be careful with any current content they upload. Whatever directions you get, be sure to follow them and exercise LOTS of patience. Don't get in a hurry. This isn't a 3-4 hour task. If you take your time and follow each step you will be quite happy.

A really quick search on YouTube showed some results for doing a P229 . . . . Keep looking and maybe you can get closer.
https://www.youtube.com/result...g+cuting+p220++rails