How do I know if I have ADHD?

I think I might have ADHD as a 13 year old, I feel like I can't concentrate much, I do that thing with my leg (yk...) ,I fidget with pencils all the time. I can't do anything without moving _except_ for when I got headphones in (ex. I go to a drawing course and the people there are super sociable but then I go see what I've done in those 3 hours of the course and I feel like I've achieved nothing because I talk wayy much except from when I've got those STUPID HEADPHONES IN). Except from all that stuff, I've noticed that I've got a ton of mental fog and that I search into internet rabbit holes very frequently. I've seen my best friend who lives really far from me recently (he went to visit me) that recently has gotten an ADHD diagnosis and since he's like, very similar to me it raised the thought that I already had of having ADHD, but one big, big difference between he and me is that he looks very apathetic which is almost the opposite of me (very emotional, very expressive etc.). I wouldn't waste my mom's money on a therapist (even if we're absolutely not tight on that) and just thinking of the shame that I might feel when a therapist might say that I just need to work harder or that I'm just lazy. my mom always says that all of the teachers I've ever had told her that I didn't have ADHD. she says "your Italian (I live in Italy) teacher always tells me that you've got very much talent... now, would she say that about a kid with ADHD? I can get like, ultra focused on videos sometimes tho, idk what that means.