Hello! Thanks for your reply!
Yes, I changed the theme, I had to delete the wordpress from server and install it again. I've lost everything I did in the last months...
I didn't know what happened, I couldn't go into wordpress to change anything, the whole site was blocked.
I bought another theme that supported Woocommerce and now I have to build all the shop again. My mistake was that I didn't know I had to do the back ups manually. I'm still learning all this.