The first thing I'd recommend is to identify all your options.
Think this way: the best thing about knowing terminology is knowing what that terminology is about.
So if you want to improve in Smash, I'd say that a great step is verify if you really know everything that is common to all characters.
- Jab, Tilts, Smash Attacks, aerials, specials, dash attack, defensive options (shield , spotdodge, airdodge) , grabs and throws, movement options (run, walk, crouch, roll, short hop, full hop, double jump, fastfall), ledge options (drop, get up, roll, jump, attack), teching, item management (catch, throw, drop)
Smash is
dense but is also simple. I know a lot of people that knows everything (or almost everything) above without knowing their regular names. I also know people who knows a lot about the game and plays like they don't, ignoring a lot of options.
After you understand your options, try to understand character specific stuff.
This is where you will find most of what people think it's "advanced play" too. Time to see when it's smart to throw a move and what moves are good in each situation. It's clear that even a begginer knows that a little. But it takes sometime to learn that landing with a certain aerial is usually bad, or that a move can be used to escape or create pressure.
- How to mix your recover.
- How to score kills.
- How to combo (not every character is combo based, but starting to combo it's a good feeling of improvement)
- How to escape combos (learn about DI and DI mixup, DI mixup is completely underated)
When you're on this step in where it goes crazy. There's a lot of stuff to learn from there and it's where the largest bunch of players stop. It's harder to explain exactly what lies beyond this, cause it branches all over the place.
- Match-up and stage knowledge.
- Studying phases of the game: Neutral, advantage/disadvantage stage, edgeguarding, juggling, etc.
- Mental aspects: Reads, how to identify patterns, counterpicking, conditioning, etc.
- Sharping your proper playstyle.
Every single Smash game until now is complex enough to never-ending learning. But you also need to play. Personally, I'd say:
it's better to play than to know. I know a lot about this game and end up losing to players who plays better. But knowledge is also power, so it's your call to find a balance.
-------------------
TL;DR : Izaw has a incredible series about learning Smash Bros. that tries to explain a lot of what I exposed.
Give it a chance and have a good time with the game.