Hi there,
I am a born muslim, also year 12, and I know quite a few reverts. Firstly I am so happy for you and just know how insanely special you are to be even considering islam. There is a lot that comes with islam, and Allah (swt) has of course taken all of that into account and he knows how hard it is for people because he is the all knowing.
I know that families can take it really hard when someone says that they are muslim and all the pregidous that comes with it, but dont let that put you off because if you feel that special pull towards islam then dont let it fade out because you have been chosen in MILLIONS to even feel that and Allah (swt) has allowed your eyes to be opened to the beauty of islam. You could keep it under wraps if you do revert until you feel comfortable enough to tell people.
To revert you would first have to read the shahadah, and this can be read with someone you know who is a muslim, or at a mosque (and depending on if you are a guy or a girl it would be in a certain area of the mosque too). Then (preferably at the mosque) you could ask the imam about the rueling on something like this as I dont know what they really are food wise. Personally I would say tell your family your a vegitarian and trying it out or something because that way they might not force meat on you that isnt halal, but like I said, im not an expert so idrk.
Sorry this sounds so childish but I really am trying. I hope this helps even in the slightest and you can always dm me if you want more information because I would be happy to help.
All the best and inshallah everything works out for you x