It can definitely get crowded, but the noise impact depends on where you camp. Most campsites out there are meadows with maybe partial line of sight. At you'll find that the packed weekend trails, though, will vaporize once it nears sunset as the dayhikers leave.
Use the phone number for the NPS, at the URL listed above, and they'll give you a pre-recorded message saying which campgrounds are full which weekends. It's invaluable for trip planning.
I did a solo overnight out there last year; it's easy to link trails together for any level of difficulty or length. I did two 14-mile days and it was great..I think I went in August (super foggy, weekday, only a handful of other folks out there overnighting).
Point Reyes is like any other hiking destination on the California coast: beware of ticks, watch for intense poison oak, keep in mind the fog factor, and such. Wildcat Camp, at least, has food lockers and picnic tables.