I looked at the Washington State bicycle association website and it appears your state has a 50+ category that allows Cat 1-5 to race. Generally speaking this is a lot safer than racing as a 5 or 4, but the level of competition would be tougher. If it was me, I would race 50+ and get better that way. Most associations will still let you cat up (especially 5 to 4 and 4 to 3) using Masters races. Also if you have a local club that has 50+ racers that might be a good place to start as well as you would get to race with teammates who have experience.
__________________
My slightly narcissistic and rarely updated blog can be found
here