Paula, Welcome to MOAC. I’ve always considered the Evans Notch region on the Maine/New Hampshire border (Rte 113 north of Fryeburg) as a kindler, gentler part of the White Mountains and a perfect introduction to hiking with some elevation thrown into the mix. The peaks there are all in the 2000 – 3000-ish foot range although depending on the height at the various trailheads, the total elevation gain is much less.
As far as what to do when an event is posted, read the description and if it seems like something within your ability, contact the trip leader listed in the event posting. They’ll be happy to discuss with you the particulars about distance, pace, elevation, etc.
I second Bill’s suggestion that you come up for Summerfest and we can talk about what to pack. Would love to hear about your experiences on the Camino de Santiago as well! My email is email@example.com.