ipad reset but stuck on old apple id

so my ipad air 2 does not work only if u log in into your old apple id wich i know but i dont know the password and i have two step verification on and for that two step verification i need my old phone number wich i threw in the trash because i had a new one. and now i cant do ‘forgot my password’ and im really sad cuz it doesnt work anymore. but long story my mom repaired the ipad wich was broken and we didnt use it for like 2 years or 3 or so, but we reset the ipad fully only it needs the apple id and the password (wich i dont know) i hope someone can help me.