The slips in wellfleet harbor are not great, for the most part, they don't use finger piers, you have to tie to pylons at the bow and the dock at the stern, backed in. I did it one season on vacation. Also the tides run super low in there but its doable. So keep that in mind.
You can't beat it for convenience though come around the corner and you have hundreds of choices for fishing. Billingsgate is close, we used to killem' there.
Harbormaster is a great guy and will help people out even during high season. I might still have his cell.

not sure.
This was in mid summer, I don't know when is best nowadays...
Have fun..