The long term investment is a really important and great move for you to earn huge amount of money in the future but the thing about it is what coin should we invest, there are some good altcoins that can be good in a long term, my number one choice is ETH followed by BNB. Solana and ADA are also good, you can check it try to go to their social media platform and you will see how active they are.
Still, the best thing for you is to do your research, that would be better than just relying on others.