help me making some of my first financial decisions! please!

I just turned 21 and through my college's clout I got an sbi elite cc with 75k limit LTF and icici emerald CC with 75k limit LFT (2 cards, mastercard and amex, limit shared)

I have some cash (~95k) that I've saved up and want to put them into mutual funds

this is where you guys enter, please help me

-> choose a mutual funds app/ broker

-> best card / way to ape into the mutual funds ( I wanna do a lumpsum above 50k so yeah)

any other suggestions you got are welcome too, anything that helps me save some bucks, I don't think I'll use any CC points this year, tbh I don't even know much about them

your help will be deeply appreciated 🙏