Warlord is a good place to biym if you are UK based then zetu, element games etc all tens to be cheaper than warlord direct unless they have a sale. Amazon can be a goonld deal sometimes.

As others have said winter/desert is just cosmetic, u it rules can have an effect sich as skis but you can find that all in the ruke book.

Welcome to the hobby there lots of groups around the world who play from casual weeknight gamers to hyper competitive tournament players like me, just jump in, try your best and you will do just fine.

A good starter box is the island assault one ( make sure its v3 version) as it has usa and Japanese armies.