So this is going to sound really weird, but any pack you think you want you should check the back of it before you buy it. Specifically what you want to look for is where it was manufactured. Cards produced in the US have been of utter trash quality for years, especially in regards to foils which almost immediately turn into pringles. If you can't find packs produced outside of the US, then just make sure you understand you're risking pulling damaged cards.
Also, just because they're produced elsewhere doesn't mean they'll not be in English necessarily. For example my LGS has been pretty good about getting packs produced in Japan, which also have a small premade tear point on the pack US packs lack, and they're not in Japanese.
As for what sets you should buy, that depends on the format you want to be playing. Cracking packs can be a good way to give yourself a starting idea before jumping into singles if you've been out for a while, but you'd need to
consider if you're looking at Modern, Standard, Commander, etc.. For example, Modern Horizons 3 and Commander Masters have good cards, but if you're aiming for the Standard format they're both completely useless to you.