I haven't done any offshore
sailing so far so can't really comment on practical things. But if you can, it's worth taking a bit of time around the Channel Islands. I live in Jersey and it's a lovely island. You can explore Alderney first, then drop down to Guernsey, Herm, Sark, and Jersey. The French town of St. Malo is very nice. Beware the big tides in this area.
What a trip you're doing! I'm very jealous! Can't wait for my own boat
to be ready and sail from Lelystad to Jersey at the end of summer.