Welcome!!
We all were rookies at one time. Take your buddy up on the offer of instruction and beer. Beer and sailing have gone together since forever.
The 18 has a few more strings to pull than the 16 but you'll both figure it out. Start off on the lake to get some experience and then hit the ocean.
You'll get a lot of responses here. Post your experiences and ask a lot of questions.
I was in Lincoln City years ago to work on a telephone system. I stayed at The Inn At Spanish Head. Is the first floor still blown out from winter storms?