Bought land in Parrita to start building a home there. There's another member here Arenal who might give some good insight too - she and her spouse are thinking retirement there a lot sooner than us.
Ideas - we live in between NYC and Philly - and have both traveled in large cities solo . . .
San Jose is not this big tawdry seedy place.
Manuel Antonio - beautiful beach. Pay a tour guide to take you through the park. Not sure of your budget - but Gaia Hotel is wonderful. Small boutique hotel and breakfast is to die for.
The sunset in Manuel Antonio is a big deal - stop into El Avion. Great place to watch it.
Sodas (like a cross between a diner and convenience store) have really good "typical food" if you want a quick bite.
Arenal is beautiful - do a rainforest walk with a guide - you will get more out of it. Also do a hike with a guide to the Volcano up there. If you don't want to have to do a long expensive excursion to take advantage of the hot springs, then stay at The Royal Corin. Their springs are the same with a beautiful view of the Volcano.
Another Volcano - Poas. I wouldn't do a tour group for this. Stay in San Jose a night or two - suggest the Alameda de Golf Cariari. Another boutique hotel - breakfast is wonderful.one of the women makes really good fruit breads. From there, get up early and drive up to Poas Volcano early morning. Along the way a lot of little shops and artisan places. Note them for your way back. You need walking shoes - you walk up on a paved/stone path. Then you wait. We waited an hour - while several tours came and then had to move onto their next stop
When the clouds cleared - the most stunning thing I've ever seen - more beautiful than Niagara Falls. I'm hesitant to link to pictures here on my social media but the Poas Volcano is beautiful.
This is high level but things you can do in a week.
Our first trip we flew into San Jose, paid a driver to take us up to Arenal. Worth it to sight see. Cabs are inexpensive in La Fortuna (Arenal Town) and there some great local places.
Then we flew to Quepos (Manuel Antonio airport). You could do maybe 9/10 days - if you wanted to drive from Quepos back to San Jose. That's a really easy drive. You also get to stop at the crocodile bridge and check all those crocs out.
That's just a high level first timer trip. I know all of the new "all inclusive" spots are in Guanacaste - I just don't think you get the real Pura Vida unless you go boutique/small hotels, sodas, tipico restaurants.
Let us know if you need more ideas as you plan your trip.
One cool thing we did our first time to CR in Manuel Antonio - Damas Mangroves on a boat. You are literally this television show for the Capuchins. Yes, they are very very cute but they are also very very VERY naughty. Like - made lovey eyes at my husband as the stole his hat. Then the little rascal gave it to me and kept teasing him.
It gives you a different mini eco system from the mountains and a sense of the power of water.