I took a solo trip to Costa Rica at the beginning of March 2020, right before COVID hit the United States.
You will most likely fly into San Jose International Airport. I made the mistake of staying the whole week based in San Jose and lemme tell you, there's almost nothing to see or do there. Sure it's the country capital, sure it has a town square, but nothing that you just HAVE to see.
Here are some photos from the few sights in San Jose:
(As I was walking around this area, the police told me to take off my necklace to not tempt any thieves from stealing. I was also approached my many hobos in the San Jose area in general)
I stayed in this cute Airbnb which was a families' home and yoga studio. The location was close to the city (about a mile walk) and only $13 a night.
I took a couple day trips from San Jose. One was to Cartago, which also did not impress me much but I just had to get away from San Jose.
This basilica is named Nuestra Señora de Los Angeles and is free to visit. I took the local bus to Cartago for less than $1.
The other day trip was to Jaco Beach. Now this area was the place to be, with beautiful beaches and cute beachy areas surrounding!
I took the bus Transportes Jaco S.A. bus for $6 each way. I suggest getting to the bus station early (about 30) minutes, because there is only 1 bus running per hour, and the spots fill up fast.
PRO TIP: Buy your returning ticket at the same time, since buses fill up fast.
If you're traveling to Costa Rica, don't stay in San Jose. Travel around the coast by bus - I wish I had!