Hiking in May?

My wife and I are considering our first visit to the St. John's area for our 25th anniversary the third week of May. We love the outdoors hiking, backwoods camping etc. and of course Newfoundland looks like a great place to visit. I know it's highly subjective and the weather has a reputation of changing drastically quickly but would love some opinions about visiting that time of year. We don't want to go later in the season due to the anniversary. Plan would be fly into St. John's, rent an Air BnB for the week and explore the area with an emphasis on outdoor activities. Thoughts? Recommendations on where to go and do? How bad are the bugs? Blackflies in May in northern Ontario where we camp can get to be a bit much. Would we want a car everyday or is there good hiking within walking distance of St. John's? Gros Morne is too far, where else on the East coast is a must see? Is it feasible to get a sea kayaking tour in St. John's to see icebergs or would we have to do a day trip somewhere? Thank you in advance :)