Feel completely lost do I have any chance plsss help meeeeee seniors

I was neet aspirant but I failed so I am thinking of joining cs in tier 3 college , have few questions

》I don't know anything about maths (11 and 12) should I learn everything or few topics would be suffice

》Can I still have successful career or is it over already for me since I am going to be from tier 3

》any advice in general about this field