You can get hearts with Bernard if you spend the night with him in the cottage in the forest ( on Friday, between 18:00 and 00:00) or if you meet with him in Hot Springs ((you need 1 heart for this) on Saturday/Sunday, after 18:00.)
(Don't forget to talk to him before you go any of these locations "Ask about the hunt" and " Talk about hot spring " talk options)
Check your mission log often. It will tell you what to do or where to go.
The fair event is available after you build a fair at Bareshade (to do this talk with Bernard). After it is built you can go to the fair with people you invited there on Sundays.