Newbies need to understand that you don't need a whole coin to make profits. Even though you can own fractions, invest in good projects. Don't buy shitcoins just cause you can get millions of crypto for a small amount.

I was in college the other day and heard this one guy talk about shiba inu, and was like how he invested $100 in it. In my country $100 is a huge amount.

This is what he was saying "guys, if Shiba inu goes for even $0.01 we'll be rich af.", "bitcoin is expensive so buying this is good".

I want to explain to him that he's wrong and teach him about market cap and stuff but ik he's the kind of person who won't listen to others and I'd end up being a laughing stock.

This is very common mistake. Everyone thinks big coins are expensive. You can buy crypto in fractions. If you buy $100 worth some coin and that coin goes up 10%, your $100 also gets 10% rise.