Accept the Lord Magnezone as our one true God. He fainted for your sins, and was Magnet Risen from the grave. His power shall Magnet Pull you through Reborn; like a compass, He shalt point the true Way.
Seriously, Reborn is one of those games wherein six Pokémon is not enough to get you a complete or comfortable experience; very often one will have a full box of reserve team members to fall back on. Don't be limited to six, although you're always free to use even a Rativate if you want. Consider using a powerful starter like Greninja, Feraligatr or Blaziken which can be extremely helpful throughout your run (Gatr can be found later in the game, though, so the frog and the chicken are able your best bets)
As for meowstic, it's indeed a good Psychic type for early game, but later on you'll find many, better options: Gardevoir, Alakazam and even Metagross if you're willing to put in the work to catch, raise and train it properly. (Top tier Pokemon are very rare in this game)
Likewise, Lopunny and Glaceon life or on their worth later in the game! From a purely statistical and competitive point of view, Stoutland, Diggersby, Porygon-Z, staraptor and several other normal types outclass Lopunny while Glaceon is just inferior to Mamoswine as an ice type and Umbreon or Sylveon as a defensive Eeveelution. Arcanine is excellent, though. Make sure you get a Growlithe with Close Combat and level it up to lv45 before evolving it, else it won't get Flare Blitz, Crunch or Heat Wave.
And PS: use Magnezone, if I haven't made it clear already. One of the best mons in the game, and magneton is available relatively early, though evolving him is challenging.