put the cart before the horse
US /pʊt ðə kɑrt bɪˈfɔr ðə hɔrs/
UK /pʊt ðə kɑrt bɪˈfɔr ðə hɔrs/

1.
to do things in the wrong order
:
•
You're putting the cart before the horse by buying furniture before you've even found an apartment.
•
Let's not put the cart before the horse; we need to plan the budget first.