Just to get my facts right.. this game is go aroubd to level up, something like maplestory yah? I was trying to follow the story until the castle there and can glide... I can jus ignore story jus grind?
there is no point to grind at early game..
a lot of character building is based on the artifact stats which is entirely random and depend on your luck. And the last tier of the artifact (gold, Max level 20 with 4 substats) is when you reach AR45. that will guaneratee you at least a gold grade artifact with every run of the domain (20 resins)
So at early game .. don't really need to grind anything at all... just chong the story.. and the story doesnt really required you to have a build character.
from my experience , 1st thing u need to do is collect the all geo and Anemo culus first to upgrade the statue of seven .. that will build up your stamina.. which make exploring much easier. And try to get and upgrade the teapot house ASAP cause the sooner you build up.. you get to buy 60 resin and the level up book weekly
then for training character.. the base free 4 star.. i don't think you want to spend too much resources on them . maybe Lisa ..
Some of 4 star that people still used at end game
xiangling (Can get a free copy at spiral abyss)
Novelle (Can heal and shield , work with furina, beginner banner)
bennett( Attack buff , healing)
Xingqiu (strong Sub DPS)
Fischl (strong sub DPS , Great Battery)
Many other 4* are good only when u max constellation and also depend on your team .. Example C6 full constellation Sarah. I will never build an electro team without raiden and sarah .. she work really well with raiden shogun (electro archon.) cause i remember she give 60% electro crit damage .. but if you are not using an electro team.. then Sarah might be useless to build or be in a team.
If you decide to go F2p , then i suggest you just enjoy the early game first.. then decide on what team u want to build .. then choose your 4* stars build your 4* accordingly.. cause i think for the first year or so.. your materials are in scarcity .. not enough mora, level up material.. for you to upgrade all your characters .. unless you are paying