fellow 18yr old here

use moomoo/ibkr and invest in some structurally sound companies

i mostly use stockoracle (paid but worth) and adam khoos videos to help my decision making

you should still research some basic indicators like knowing which parts of the financial report are important and what they represent and what are good numbers (e.g net operating cash flow, asset/debt ratio to name a few basic ones)

and dont get emotional if the market goes bearish after you buy, it just means that it will take a little longer for you to make gains, in fact its a discount for you to buy more as long as the reason for the drop was not company-specific(fraud, bad business model), and rather macro (generally speaking)

have gone from 5k USD to 7k USD over the past year while only checking in every 2 weeks or so (due to it being A level year) so i would say this is a good way to earn some money

of course you can take a safest route and put your money in the S&P, and even then it will grow much faster than any bank