Can I get a regular engine wash or would I mess up something?
Do it yourself. "Shop washing" might be too careless...they use diesel and stuff. Bleh.
use a light water spray to wash down some vital parts. (Cover the alternator and electronic connections with a plastic bag).
Buy some engine degreaser, and spray on the engine components. Let it sit, and then wash away. After doing this, start the engine, and let it run, with the bonnet OPEN, to let the vapours which form (from the water/degreaser mix) to escape, and so, dry your engine. If you leave your bonnet closed, the engine will dry, but those vapours will leave a film on the inside of the bonnet.