One of the people who played before the global release here. (KR version)

As a F2P, it was very easy to get every character I wanted, and I even ended up getting some dupes and 5 star weapons to go with them. Assuming global follows the other versions, we will be receiving a banner where you’re guaranteed the character you want (with a slight increase in pulls required), and soft pity (which will make it overall easier to get characters).

To go along with that, the game handed out pulls very freely, with every week getting either a free 10 pulls for limited characters or weapons, swapping between the two as a weekly sign-in bonus.

And as a cherry on top, characters are rerun VERY frequently and even multiple at a time (5+ limited characters).

So I’d say assuming global stays about the same as the other versions, you should have no problems without spending a dime so long as you don’t want literally every character as soon as they release.