Could you please suggest something interesting outside Doha?

From memory:

1. Mangrove forest, kayaking (but everything depends on the tides)

2. In the north, there are forts and sculptures (if you start sightseeing tours, you will definitely see them and the highlights)

3. Camel races, and it seems there is a museum of the sheikh nearby that you can visit (but there is no clear information about the races, you need to check day by day)

4. Panda House

5. Sealine Beach - many consider it a good/best beach (but more and more often it becomes affiliated with jellyfish 😁)

6. Not far from Doha, there is also Wakra, with its own market

7. And there is an inland sea, but you can reach it through a safari

Lusail and Education City are more associated as part of Doha, but I will also mention them just in case