>>54256266I think you'd have a better time with the Mew VMax and Palkia VStar decks, as they're much closer to meta as is. With them you won't have to buy many singles to switch out as most of it is already provided. They also come with booklets that have suggestions for learning.
The cheaper EX Decks like Lucario, Ampharos, and Tinkaton are alright but they're strictly beginner decks. While they wouldn't be unusable, it's a lot of Stage 2 evolutions and without Rare Candy it just makes them harder to play. You could buy those, but if you plan on actually competing you'd want to buy even more singles than you would with the previously mentioned ones and have to swap even more out.
I got the Palkia VStar deck and gf got the Tinkaton deck ourselves, I ended up buying myself a bunch of singles after figuring out what I wanted but I bought her a whole new deck (via singles) because to get hers to work would've been a lot more expensive.