Best build for Ganyu?

There are 2 ways to build ganyu.

Freeze: You need a hydro apply unit like Xingqiu. You apply hydro and then target the weak point of the enemy with your Ganyu. The enemy won't move because of Freeze.

Melt: For this you use the Freeze team mentioned above but use a pyro unit with a switchable burst like Xiangling(Her burst stays up after switching characters). You freeze and Melt multiple times.

The best 5* weapon for Ganyu is the Amos' bow and the best F2P weapon for Ganyu is the Prototype Cresent or the hamayumi. The best artifact set for her is Blizzard Slayer with 4pc bonus.