I’m 18, and I’m looking for a kind of “sit it and forget about it” kind of investment

As the title states, I have been 18 for a few months now, and I feel like it would be smart to invest my money. I’m at a position where I could easily move 200-300 dollars per month into an account or something and still have money left over. I want these funds to build and accumulate over time, but I don’t even know where to start. Would you guys recommend anything where I could just move a bit of money every month and see results over time? Thank you.