Anime fans, would you please help me? 🙂?

The latest season of My Hero Academia is ongoing, so while it would take a bit of time to catch up, it would mostly depend on whether you want to be part of the currently viewing community (as some sites have a comments section which is at the peak of activity when the anime is fresh and anything beyond that is likely to be ignored). That is to say, if you want to be able to share your thoughts on each ep, then you'd have to watch it alongside everyone else in order for anyone to read your comment.

At this point, this is the most relevant argument, assuming it's within the scope of your interests, so in other words, you would watch MHA first to catch up as quickly as possible to be able to take part in the community element of anime viewing, followed by Cowboy Bebop, which could then be quite easily slipped in-between two eps of the current MHA season, or even left for after it ends.

If, however, commenting on current eps is something you are not interested in, then perhaps watching Cowboy Bebop first would be the right choice, as the time required to watch it and the previous seasons of MHA would delay your catching up to the current eps of the most recent series, so more eps could be out by the time you get to them, so you wouldn't have to wait as much for new eps. This option also lends itself well to marathoning MHA, which you will most likely want to do once you get into it.

First things first, your just starting Cowboy Bebop, you've been missing out!

And for the main question, ( I would watch Cowboy Bebop first only since its a classic and a lot of new anime lovers haven't heard of it, but My Hero Academia is great too!

Cowboy Bebop sound nice to watch first. But it's up to you if your want to watch first. But that's your decision. ☺