this is wifi so it's hard to say. Kirby is very different offline, actually much better. But it's okay, we have to start somewhere. Luigi is buffed like hell on wifi, as some of his "wifi" combos are hard to di out of. Keep that in mind.
You need to work on your u-tilt follow ups, but then again this is wifi, and the connection looked poor from what I could tell. Normally you can follow up a b-air after an u-tilt.
You didn't go for grabs on Luigi, and this isn't entirely bad because he can n-air you out of your grab or gonzo combo.
You seem shy with using u-tilt, dont be afraid to use it more than once esp at low %, it has great juggling ability because it has low knockback. It's also a quick and fairly safe move, altho it can be shield grabbed at times.
You don't seem to know many fundamental Kirby combos, so I would suggest reading Timmy's guide or watching videos.
You got a great read with the hammer, good job.
Nice stage spike on the last match, it's good that you know how that works because it's very useful.
Keep training your Kirby, but try to get offline.