My hair was basically like yours in my early 20s. I'm 44 now and only in the last few years have I had noticable hair loss.
At your age it's tough to say what will happen but I'm pretty sure you'll be fine for at least another ten years. Just keep an eye on things, take pics and KEEP them on your phone for YEARS so you can compare in 5 and 10 years.
When you're 30 you may want to try finasteride or some other treatment. I think you're good for now though.
I have no clue what happens with trans people, what type of hormones they give you, etc. But I'd still take and save pics.