1. I ordered some Abena Abri-Foam M4's as a first diaper, (Was that a good idea?)
Abena M4's were the first real diapers I bought for myself, definitely a good first choice!
2. If it's a good idea to come out to my parents, how do I do it?
Quick story: I got outed when my folks caught me with a Goodnites pant on underneath my jeans, and they didn't take it well, to the point where I was made to get professional help. Though they've relented to an extent, I know they aren't a huge fan of it.
For a lot of parents, mine included, it's a very difficult subject to approach. In my personal experience, it's best just to avoid the subject altogether, unless your folks are really open-minded and don't mind too much about what you choose to do with yourself. It's easy for people like us to get why you do it because we're all like-minded in this department. Parents, usually not so much.
3. Any tips you kinda have for beginners?
I know a lot of this will be repeat by now (probably), but first things first, take it slow. Explore at your own pace, and don't feel like you have to obligated to do certain things. Do whatever feels comfortable to you. It took me a while, but I started to get more into the AB side of it, with onesies, pacifiers, stuffed animals, and that sort of thing. You might surprise yourself about what you discover while exploring. I will say this, though, sleeping in diapers is an amazing feeling. For me, there's a great sense of comfort and relaxation while sleeping in one, and honestly, I think they help me to sleep better.
Another thing is try out different diapers, and see what works best for you. A lot of folks have a preference to one or a few based on how they fit, how they look, how they perform, etc... There's enough of a variety to suit just about everyone's tastes, and eventually you'll find your ideal diaper.
I know it's been discussed, but try to avoid the binge/purge cycle. I've gone through it enough times to know that throwing it all away when you begin to question yourself isn't worth it. If you feel like you are getting overwhelmed, pack it all up and put it somewhere out of the way. With enough time, you'll probably end up coming back, and instead of starting over, you'll have all of your supplies ready to go for you next adventure.
A trick I learned with those M4s, because you can only tape and retape a very few number of times, try to use either packaging tape or duct tape to make a landing zone on the front of the diaper. The tapes are very sticky, and will rip the plastic on the front of the diaper once attached.
I hope this helps, and if you have any more questions, don't be afraid to ask. We're all here to help.