Accommodation in Cologne.

Hello,

I'm Aitor, a Spanish guy who will go to live in Cologne since next January.
The main problem is that I can't find any apartment or flat to share. I have been seeking on Wg gesuch, but there are not to much or so expensive rooms.

If anybody can help me, I am being very grateful and maybe I will invite some beers at my future home.

Danke Schön 😁

German landlords are conservative and will not agree to rent to you before having met you in person. And you also should not agree to rent a place before you viewed it.
Thus you should arrange temporary accommodation (e.g. hostel) for the first weeks and start your flat search after your arrival in January.
As for the price: You are unlikely to find anything cheaper than the rents advertised on WG Gesucht  - if you cannot afford that, don't come.
The housing market is currently VERY difficult, everywhere in Germany, and prices are going up tremendously due to the refugee problem - the authorities are renting all available apartments to house them!