We went to Bruges and Brussels (and Ypres and Waterloo!) a few weeks ago. To be honest it was a bit hot for us to really enjoy it. You should have better weather.
As others have said, Bruges is gorgeous just to look at. We watched the film 'In Bruges' on the first night for context!
Unfortunately lots of places are shut on a Monday which scuppered our plans but we still had a lovely time just walking around. We went up the Bell Tower for the view and went on a canal boat trip. I think the quality depends on who is captaining the boat. We also went into churches that we might otherwise have missed.
We couldn't do the Brewery tour so we went to a Beer Cellar instead and ordered 'paddles' to try.
We went to the Groeningemuseum just before we left. It has art from over the centuries, all from artists who were based in Bruges.
In Brussels the Grand Place was stunning. Like a gilded version of the Bruges buildings. They also had a carpet of flowers while we were there.
We went to the Magritte Museum (because he is actually Belgian ) which was amazing too.
The EU museum was free and really interesting. Lots and lots of information that you can dip into. A bit sad to see the 'UK left' panel.
I can't recommend places to eat because our focus was vegan options rather than quality.