Got into dating super fast and confused on what now, help :|

Through 2022-2025 i (17M) had a pretty major depression and started recovering since the end of summer 2025. About 1-2 months ago as my school (not normal school, only on weekdays and once every month) had its last days approaching a girl(17F) approached me and started acting friendly to me, mind you this was the first time someone approached me and wanted to be friends rather than me for like 4 years by that point. So over the next few school days we got along quite nice and when the school ended i asked if we should stay friends not only in school but in life in general, so she said yes and we got each others numbers. And so we started chatting more often and now as friends.

Then in about 1-2 weeks she asked if i wanted to hang out, and like cmon i'm not about to say no to get out of my house. we talked for a total of about 3 hours, basically the whole time just sharing personal backstories and what-not. After that my heart was racing because i just understood what i've gotten myself into.

Fast forward to the future about 3 weeks and i am on this third hangout where i just casually ask about her sister dating (not in that way, it was the smoothest transition in my mind because i know that she was dating from school) and she then asked me if i wanted to date which my mind just did not expect like at all so i just said with heavy hesitation maybe because i knew that i was by now definitely attached to this "relationship" and i felt like i had something going so just couldn't say no, landed on maybe as the best choice. After about 30 minutes i asked her if she wanted to date in a joking tone after which we got into a heavy argument (filled with jokes and serious questions) after which she just calmly said "Sure".

So here i am, after 4 years of only talking to my best friend in a matter of 1.5 months i got myself a girlfriend. not very social person and still somehow i stand here. and also the first now date and not a hangout will be in a matter of days and i still am kinda shocked/confused.

I might not explain everything clearly since English is not my first language but i think i got the point through.
This is my first ever somewhat real relationship so i am confused and come here for some wisdom from people who know probably more then me.
If you read this whole thing - thank you (it took a while to write out), and if you have any advice - i would appreciate it greatly. Thanks and have a good day :D