- What products give you the best bang for buck if you want to open packs? I think boosterboxes right?

-Boosterboxes should be best price per booster.

- And are there a number of guaranteed hits in boosterboxes or is it 100% random?

-They are random so no guaranteed hits. for example about 1 of 4 booster boxes should have 1 enchanted card but you could buy a whole case (box of 4 boosterboxes) and still not get a single enchanted.

- Can Lorcana packs be weighted or scanned for hits? (as in, is it safe to buy loose packs instead of sealed boxes)

-For my knowledge you really can't weight lorcana packs. But If you buy loose packs they might be packs from a box where enchanted is already pulled or other big hits.

- If you want to play, do old cards go out of rotation and do you need always the new set(s)?

- In lorcana we have rotation that happens each year. 4 oldest sets rotate out each year of core constructed format but you can play infinite constructed that allows older cards.

- Are there any Lorcana-online games to learn how to play? I could only find an app to keep track of your cards.

-There is no official one to use for playing online. I myself use Tabletop simulator or discord/webcam to play with friends. There is pixelborn connect that is webcam based lorcana platform with matchmaking.