Well, I don't play Corrin at all, so I can't offer any Corrin-specific tips and tricks. But, I'll try offering some general advice you can use.
Being a swordsman really helps Corrin in a way that he can pressure his opponents from afar. Knowing how to pressure a defensive player is important, since this kind of pressure will likely cause a reaction out of your opponents.
When you're trying to pressure with a short hop fast fall aerial, remember that you can either pressure them with those moves, or you can just land without using any moves and just grab them if you think they're going to shield. Or, since Corrin's f-smash is quick, if you think they're going to drop their shield after you land on the ground, you can land, pivot backwards, and f-smash to punish them for dropping their shield. (Of course, you gotta be careful where you land to avoid their OoS option.) And, of course, there is always a tomahawk option.
If you're trying to pressure from the ground, there are several options. You can dash attack if you think they're not going to react to it or punish it. You can also dash grab if they're shielding and they're not going to react to you fast enough.You can also walk if you wish, since it can cancel into any move. But Corrin's walk is pretty slow, so I would be careful with this. Aaaand, obviously, a common way to punish landings would be to dash attack.
Another thing I want to say is, if you want to be an "aggressive" player, you should always try to extend your advantage state. If you win neutral, combo your opponents. If your combo ends, read your opponents' next actions, or try to force them to play your game so that you can reset your advantage state.
Last thing. Since Corrin, as you say it, lacks in the mobility department, it would be harder than usual to be aggressive as him. To compensate for this, try to use your projectile smartly. Good projectile usage will force your opponent to think twice about just camping you. Of course, if you start spamming it, your opponents will read you and punish accordingly, so be careful. Another thing you might want to do is position yourself properly. Being in that good distance from your opponent will allow you to charge in without being too obvious. This distance will vary for different MUs, so be careful.
That's all I gotta say, really. Sorry if what I wrote doesn't make any sense; I'm kinda tired right now, so I might have written down some gibberish you might not understand lol. If this is the case, I'm more than willing to clarify what I wrote. There are a lot more to being aggressive than this, however. Those stuff are some things you gotta find on your own. Try out new things, get a feel for it, and develop your unique playstyle. In the end, the thing that will really help you is experience.
Good luck with becoming the aggressive solo-Corrin player you are wanting to be!