I haven’t read it myself, but the trans reddits would always recommend this site as a good starting point: https://genderdysphoria.fyi/en

Some small stuff I found helpful when I was just realising were a bunch of articles I’d read on some basic things like how to tuck properly or how to style longer hair in feminine ways (since I already had long hair, if you have short hair there’s probably articles for that too though). Unfortunately I didn’t save them and the few I did have been deleted since then, but there’s a lot out there on this stuff that a simple google could find. Practicing with these small things are really helpful for getting a more concrete understanding of how you relate to your gender.

If you live in a more accepting place then there are likely some local resources which will be helpful too, especially since they’ll usually include the info of local groups or doctors.

Personally a lot of what helped me figure it out was just hanging out in trans spaces as a lurker and realising how close everything felt to my own experiences, as well as discussing it with a few trans friends I had. It took me something like 6 months of active questioning before I started to lean more on the “I’m trans” side than not, and another few before I felt any degree of certainty.

Also keep in mind while questioning that it’s perfectly fine to not figure it out right away. You might try being “just” a binary trans woman and then find you’re more non-binary or vise versa. Desisting/detransitioning if you realise after a while that maybe you aren’t trans is fine too. Ultimately it’s a process that takes a while for anyone to reach any confident conclusions on. Just try to make sure you aren’t being pressured into any specific interpretation of yourself by someone else: what matters is who you are.

Sorry there’s not much in terms of concrete links here, I got a bit carried away with my usual babytrans big sister-ing. (And I just don’t have many links saved) If you want to discuss anything feel free to ask me about it.