Based on the limited knowledge I was able to gather during my short visit, here is what I can advise if you decide to visit Latvia

Wander through Riga. The city is pretty awesome, architecture is fascinating, and it isn’t overrun by tourists yet
Visit the Baltic Sea. If you go in the summer, you can swim, but I’d imagine that it looks gorgeous in the winter too. Plus its really easy to get to from Riga.
Get into the countryside and see the forests.
Get involved in an old pagan tradition.
Find random hole-in-the-wall places. They’re really interesting and unique here.
Be there for the solstice.