Learning to love the learning process will make Melee a lot more enjoyable.
Right now I'd focus on solo practice. Sometimes do some practice with people to see if you can apply the stuff you practiced solo, but you need to spend 90% in solo practice; you don't have the muscle memory yet, and you might get discouraged if you get bodied too early.
If really new, I'd suggest spending a solid 1-2+ hours focusing on a very small list of specific things you need to learn. Mastering fundamentals give you the building blocks to learning the slightly more advanced stuff. And then you build off of that to learn the much more complex stuff.
The reason you want to spend a lot of time upfront is that some of the motions are still new. Your brain and fingers need to parse through all the inputs. You need to know why something works the way it does. Ex: Wavedash is 2 elements. Jump then airdodge. But you have to learn the timing. And it's technically 3 inputs. Jump button, then airdodge button + control stick angle. Your mind and body needs to figure out what works (which jump button works for you?). Then you find out that you MUST push the L/R button down all the way to get the analog press to trigger airdodge. After that you need to get used to angling the stick for the effective wavedash distance. And of course the timing as well. If you do it to early, you only jump. If you do it late, you do the awkward "triangle jump."
So for Waveshine it builds off of wavedashing. It's a wavedash, but you shine before you wavedash. Of course that comes with its own complications like when exactly can you jump out of the shine. Practice and timing. Then you practice some more against a body or a shielding body. That's 3 separate scenarios to practice. Don't assume you've mastered anything and stay humble and patient. Be patient.
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Once you've spent a fair chunk of time breaking the motions down into its elements and building it back up, that's when you can start adding speed and doing it quicker. Then add repetition. Just do those singular motions over and over.
Then take a break.
Do it again the next day. Rinse and repeat. Each day you go back, you can afford to spend less and less time since you're not really trying to rediscover the motions anymore. You're now just trying to relearn it. Eventually you can just spend maybe 5-20 minutes each day on just that motion. It shouldn't be like the early days where you spent 1-3 hours "labbing out" how to do something.
The caveat is that if you're still stuck or something just doesn't feel right, then you might need to go back to one of the long sessions to re-lab out what you think could be wrong. And ask questions. Always ask questions just like you're doing here. Whenever you come back here or on a Discord, come with questions. Come with broad ones then over time they should become more specific. I did this for just about any and all techniques especially the ones that gave me a hard time like running shine nair and shield dropping. Shield dropping was such a plague for the longest time for me. But I finally bit the bullet and did some dedicated practice and now I have most of it down.
(Also this is a sidenote: Sometimes even after you've mastered something, it's good to go back and just check up on it. Make sure that what you're doing is correct. Double check the engines, if you will)
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To revisit your question on balancing it with school:
Just need to make the right life priorities. School should come first, but if you want to learn Melee you also just need to bite the bullet and accept that you're going to have to set aside some time for it as well. It doesn't need to be a life-changing thing, but discipline is key. You should approach Melee the same way you'd approach a musical instrument or sport. Practice and accept that you may be bad today, but know that you'll be better tomorrow.
I'd suggest maybe a dedicated 1-2 hour block once or twice a week (on a weekend maybe?) and then try to spend maybe 5-30 minutes each day practicing. The hour-long blocks will be your training clinics where you take the time to learn the lessons (like private lessons with an instructor), meanwhile the 5-30 minutes should be treated as drills (like the general group practice). More rote memorization than anything.
Another way to think of it is like practicing math or physics. You need to take the time to really read the book and absorb what is going on and why it works the way it does. But after that you need to do practice problems and drill or "grind" them out, so that way you can do it on a test quickly without having to spend significant time, "solving it," on a test. You "know" that this formula works for this spot because you've done similar problems hundreds of times. You get to spend the majority of your conscious effort on the actual hard stuff.
Be patient. Be disciplined. Take time (and breaks). Accept that progress can be slow. Learn to love the learning process.
Feel free to come back anytime and ask more questions.
Edit: Btw, if your hands ever hurt, just take a break. Take a few days break if you need to. Long-term hand health is a very real issue, and a lot of it comes down to not taking enough breaks.
