First, I want to say, it is NEVER too late. One of my dearest friends is a trans woman who is a few years younger than me, so 27 or 28. She is CONVINCED it's too late for her. I've met her in person, and she has a very slender build, she complains her shoulders are too broad but honestly I know cis women with broader, and her face is angular and -- honestly, she'd be a knockout. But she keeps convincing herself it's too late. Please, please, please don't do that.
Do you have a good support system? Are your family and friends accepting? It's not impossible if they're not, but it sure makes things a lot easier. Do you have insurance that will cover HRT? Generally, surgeries aren't covered but HRT (estrogen, spironolactone) are covered by many.
If you can start early, great! The only concern that some have about that is making sure you know what you want, and that it's not something you're going to regret later. Honestly, I don't think this happens as lot as people worry about, but since there's a forum here for people who de-transition, it does happen. If you haven't already, I'd suggest a therapist who is familiar with gender identity stuff to talk with and make sure.
If, however, this is something you have known you've wanted for years now, then a therapist for that may not be needed. Some doctors won't prescribe HRT without a therapist signing off on it, though, but I think that's becoming a bit less common than it used to be.
Good luck!!!