Im almost 18, dont know shi bout investinh but wanna try

Hi, as u read i got one month before being 18, and i wanna start investing, not the type of investing that almost seems like luck/you have to be extremely competent to do, im talking about those really slow long term investments that ppl “say” will retire you young etc… Maybe its bs and it doesnt exist, thats why im here asking more knowledgeable people if it does exist, investing to new people like me always has that aura of something similar to just going to the casino but looking at it logica