Asklemmy

I like to just to Geocaching. There are often a lot of caches in the cities, and a lot of then often have really niche information on I teresting topics. Plus when doing earth or virtual caches, you often need to explore quite a bit.

It depends on a lot of things. Which part of the world? In Europe big cities all have the tourist part and the "old town" part. If you are there sightseeing just get a tourist map and start exploring.

You can usually get an equivalent of a tourist day tickets, which will give you unlimited access to public transport, sightseeing buses and some attractions/museums. Just pick up the one which tickles your fancy and usually you can get it from any airport, big train/bus station when you arrive.

If you are there to party and check out the night life I would strictly stick to popular spots.

For any other interests (hiking, historical spots, etc) you can find a city specific list of recommendations online.

Also it usually helps to google which tourist scams are popular in the region to avoid them.

I like to aimlessly walk around and see where I land.

I love to go on free walking tours if they're available. Other than that there is a view of most popular attractions on Google travel which you can filter by most popular for tourists or locals.

Unrelated to your question, but you seem to have ticked the option in your settings that indicate that you are a bot, so anyone with a blanket ban on bots won't see anything you write.