Yes, you can buy cub and invest it.

Yes you can buy LEO and invest it. You can also earn LEO in different ways. One of them is commenting on the ecosystem.

For example I am "upvoting" your comment right now, because of how much LEO I have invested, my upvote is worth roughly a 0.25USD, in about 7 days you will see the payout in your wallet.

If you are not comfortable buying the coins until you understand the model, that is fine. Start by reading articles on here and commenting on them. You will start understanding more, and start earning LEO and when you start seeing your wallet grow you will be able to decide if you want to put FIAT in there to make it grow faster.

Welcome and I hope you find your time here profitable.

Posted Using LeoFinance ^Beta