Cloud does pretty well against fast characters, being fast himself with good frame data and disjoints. Additionally, his projectile makes it so that they can't always dash in for free. Compared to Shulk, Cloud has a much easier time dealing with fast characters overall.
One thing to do with Cloud is using his projectile to pretty much harass your opponent and force them to approach. It's one of the best projectiles because it goes far and it can't be crouched under by characters like Kirby or WFT. A lot of things you do with Shulk, you can probably do with Cloud. Like Shulk, (pivot) Ftilt is an excellent move to throw out for spacing out your opponent. Short hop Nair is also an excellent option in neutral, and if you connect and time your fast fall perfectly, you can combo into jab combo, or Dtilt into Uair to name a few basic combos(Uair will only true if the end hitbox of Dtilt hits). A notable thing about Nair into Dtilt is that if you do fail to connect Uair after Dtilt and they did air dodge, you can fast fall immediately to loop back into Dtilt and put them in the same situation. Full hop Dair is a good approach option for Cloud because it autocancels and you can cross up shields with it. Furthermore, Dair has an extended hitbox, similarly to Mario or Luigi's Nair, but don't expect it to combo break. You can also approach with full hop Fair, which can be hard to punish if properly spaced out. Short hop Uair in neutral can lead into devastating combos, even Finishing Touch kills, but it should be used sparingly because while it does autocancel, you will be pretty open to shield grabs. Similarly to Link, you can do jab 1 and maybe jab 2 into Dsmash, but I'm not entirely sure how well it works for Cloud because I've never done it myself yet. Charge your Limit as much as possible, whenever your opponent's too far from you. After charging your Limit, you'll pretty much have to change your playstyle up a bit, as forcing approaches is no long an option and you'll have to rely a lot more on your normals. It's important to know when to be in and out of Limit, as in does the matchup require heavy use of your projectile, or does it not really matter too much?
While he's not exactly a grab combo character, some things you can do are Dthrow into Cross Slash 1 and 2 into regrab Dthrow Cross Slash 1, 2 , and 3. The 2nd hit of Cross Slash has a vacuum effect and pulls them in towards Clouds grab range. Alternatively, if you don't wanna go for the regrab, you can just go for the full Cross Slash combo after the first Dthrow. Dthrow into turn around jab combo seems to work on most characters, but you have to be quick with the turn around. You can also do Dthrow Ftilt to change things up a bit. At higher percents, you can try going for Dthrow Bair follow up, but much like most of the other "combos" listed mentioned above, it doesn't true combo.
The things I mentioned are just some of the easier stuff, but here's a video that I think is pretty helpful. I also recommend checking out The Art of Cloud thread, which can also be found in somewhere in this very Cloud discussion subforum. There's also plenty more helpful threads, so keep looking around and have fun with Cloud.