How do i start my 2000 suzuki gz 250 after it has been in the cold rain for a week?

HEET Gas treatment, removes rust and water in your tank so you dont destroy it by trying to force it to run it through, Cheap gas antifreeze and treatment and can be found in any car stuff store or even walmart

If it has only sat for a week, then your not in any real trouble. As long as your seals are good and no water has leaked into the gas tank, then it should be able to start right up.