Oil leak front engine cover (not oil sensor)

Yes... Cleaning everything and re-inspecting later is the correct way to do it! I'm not seeing anything to be alarmed about. Looks like a typical engine that may have had some oil spilled during an oil change/adding oil. What stage of engine oil loss are you at? As in how many miles per quart lost? Also, how many miles on the odometer?

 

Pretty common. Right at the junction of three parts, the head, the block, and the front cover, there's no gasket, they use sealer. The factory made a little recessed space on the front cover to hold more sealant. You can see that junction in your pic. The sealant degrades over time and leaks. Did a bunch of these at the dealer, it's not cheap. I think it's because the machining process on the aluminum leaves it too polished and the sealer doesn't have a rough enough surface to grip and it slips out.

If you are going to DIY scuff all the sealing surfaces with red scotch pad and wipe with brake clean. Get a good grey permatex silicone, or toyota brand sealer and read the directions. Apply and bolt together only finger tight. Do not fully tighten right away. Let it dry for an hour and then tighten. This leaves a thicker layer of silicone. If you tighten right away it's thin and flimsy.