I recommend you, olgaa, not to think about French, or in French, when learning Spanish. It's true that we have some structures exactly the same, but they are only a few.
I tell you my case. I'm studying translation from English to Spanish (I'm Spanish native). And there's sometimes I sink myself with Spanish because I feel tempted to use the English structures. My mates who study translation from French to Spanish often tell me they tend to it too.
So the best think you could do is to learn it slowly no to get sick with so much information, but forgeting about other languages you know, even it they are romanics too.
Any doubts you have, if you ask, I'll try to help you.

Good luck!

- Jen