How do I work out my planet's climate?

[laevex_esre]

OK. I'm creating a world called Kaliros and I want to be relatively accurate. It's not a magical world. It's for a sci-fi project.

Here's a blank version of the world on an Equirectangular map:


I want to try and work out what parts of the planet would be deserts, rainforests, forests, ice etc. I have no knowledge of climate whatsoever, but I knocked this map up today to show the kind of thing I'm aiming for:


That's probably way off but maybe it's a starting point?

To make things slightly easier Kaliros is the same size as Earth and similarly tilted. Its continents are obviously vastly different, but the land-sea ratio is about the same as Earth's too.

I've seen some of the stuff on here to do with wind direction and it just baffles me. If someone could help me that would be really appreciated.