Kopsis response is spot on. Handguns are not typically the easy first build you want to start with.

I know its not as exciting as some of the other builds, but please start with some variant of the harlot. To keep it a bit more exciting, download "BLC Presents the Harlets" which is a mega pack containing all their options. The harlot is largely modular, so in many cases you can mix and match parts to build something unique.

The reasons you should start with one of these are: They force you to get familiar with 3d2a concepts like working with barrel liner, and printing parts that move against each other. They force you to calibrate your printer. They also have good documentation that covers troubleshooting of all the common issues. And finally, the stakes are lower, both from a financial standpoint (harlot kits start around $20) and from a health standpoint, that if you blow one up in your hand, its much less likely to hurt you than something larger.

Once you have not just completed building, but testing(Firing!) your harlot, move on to a more complex build. I highly recommend one of Kaewon's builds (Baby Barrett, M4Gery, Wisp, etc) as they are generally all easy to print, assemble, and get working well, and they all look fantastic

If you're dead set on building a handgun, the YH22 or SY22 are both good options for fully printed builds. You can think of the SY22 as a deluxe version of the YH22... the SY22 is based on the YH22, but with many enhancements made for an overall fantastic build.

If you haven't already, check out the builds section of my site. You'll likely find something you hadn't seen before that you want to build!