I've never understood why Cowboy Bebop is often said to be a good gateway anime when it is unlike almost any other anime I've seen. If it resonates with you and then you watch other anime hoping for the same hit you will be sorely disappointed
Gurren Lagann is a better "gateway anime" if you want to see if you would like shonen-esque anime (I can't speak to shojo or moe stuff, I haven't watched many)