I got my doctor to do it twice before I tried self injecting in front of her.
I don't have any tutorials or anything but this is what my doctor told me, it's what I do.
I divide my thigh into three sections, and make sure to do the shot in the middle section and on the outer centre side of the thigh. Look for veins. I used to have more but for some reason they seem to be disappearing as my legs get smaller, and also there is a lot of hair there now. grab a chunk of the skin where you want to inject and squeeze it. Of course following the steps of disinfecting the area. Then just pop the needle in. I prefer to do it slowly rather than quickly because I get to feel it more. It's kind of empty feeling for a while and then I can feel when it jabs into a nice muscular area. Pull back on the syringe, I always get some air bubbles, I always wondered about that, because I don't remember it my first few times but whatever. I get very little blood after my shots, usually don't even need a band aid.
Go to youtube, they have instructional videos, I'm not sure if any have good close ups of the thigh though. I know I've seen a few before I started T and even while on T, which reminded of a few steps I was forgetting, haha. Like I have to use two needles everytime because I don't have extra um needles for the one syringe so its a waste but cheap because I got a huge box that would have lasted four years, until I started doing it every week, now they might last another six months since I'm using two as well.