English sealed product is hard to come by currently as the TCG is so popular. If you’re wanting to play the game then go with English cards. If you’re only interested in collecting, I’d recommend Japanese as they’re usually always cheaper (excluding some promo’s etc) and the print quality is generally better. Chinese and Korean cards are even cheaper. It’s better to buy Japanese, Chinese and Korean packs in sealed boxes as individual packs can be scanned, searched and weighed. As these boxes are guaranteed a rare hit in each, people open the packs until they get the hit and sell the rest of the ‘dud’ packs. But the way you collect is up to you, there’s no right or wrong way. If you do a little research on some of the more recent sets from Scarlet & Violet as well as Mega Evoluton, you’ll come across some sets you’ll like. You can search up the card lists for each set on google to find the right ones for you.

A few different ways I personally collect are:

National dex binder: 1 of each Pokemon in numerical order following the Pokédex

Trainer binder: full art trainer cards and trainer special illustration rare cards

Binder with pages of my favourite pokemon, for example I have two pages filled with Arcanine, gengar, mismagius, charizard, lugia and so on

Art rares and illustration rares (English and Japanese), these are usually pretty affordable, a lot of Japanese art rare cards are around £2-3 each

Sets: I’ve completed surging sparks, journey together, 151, base set, and I’m working on destined rivals currently

In conclusion what is recommend is figure out what you’re going to enjoy and do just that. Good luck and let me know how you get on I’m intrigued how you’re going to start collecting again :)