It will take some time to get a handle on since Pokkén is a different beast from most fighters. There isn't really a fallback game to autopilot to in order to get started in this game, but part of why it is deep in the meta is because it works so differently.
Simple inputs of Smash, the wide room of movement of most action games, the combo game of Tekken, and the beauty of Pokémon all combine in this game, and there is a lot to try out. You do need to play a lot of the campaign to unlock most if not all the options in local play, but thereally is a lot to work with. 16 character roster may not be a whole lot, but 20+ Support pairs offer a unique way of help with combat, serving as combo extenders, combo disrupters, zoning tools, recovery options, or protection. Support pokemon can help particular pokemon in areas they may not be comfortable in, such as a Machamp using a Latios to help zone a character into a guard so he can grab them, or a Sneasel using a Reshiram to help pile on some extra damage.
Alongside this, each character has the same basic mechanics: a grab move, a Counter move, and simple moves to get started. The game then centers around unique features each pokemon gets. For example, Chandelure can fake out aerial approaches with a swing that she can cancel into a move, Pikachu Libre can land a special move to charge up and power her other special moves, Shadow Mewtwo deals loads of damage but loses HP every hit, etc. The game also helps give a basic idea of each Pokémon's playstyle by classifying them as Normal, Power, Speed, or Technical Pokémon.
The training mode is really nice, offering reset options to start a combo over or options to see when you or the opponent are stuck in an animation. No 2P practice unfortunately, but the practice modes still offer some great opportunities to keep your game inproved.