I could make up a story blaming someone else but, it was my own dumb ass fault. I live and hunt in Western Washington. I have been out in the rain all weekend with my son chasing elk. When I break apart my rifle last night, it has rust everywhere

down in the nooks of the action, around the trigger, spots up and down the barrel.
Please help me fix my stupididty
1. How do I get the rust off without destroying the bluing?
2. Will a gunshop be able to help? How much would they charge? I am having a hard time finding the tools to get intow where I need to.
3. How do I prevent this in the future? I thought I had it oiled enough.