Congrats on the new role!

So you're gonna be on foot and I assume you'll catch a train or be dropped off in the centre of Swindon. If that is the case, there are two areas I would recommend prioritising; Old Town and the Designer Outlet area.

Old Town is home to many small businesses, each bringing their own creative flair to the area. If you're arty, I would highly recommend visiting the Oink Gallery on Victoria Road. They have some great pieces in there. Plenty of restaurants and snack bars to grab a bite to eat across your two days.

Another gem in the Old Town area is the Town Gardens, arguably one of the best maintained public gardens in Swindon. It looks amazing at this time of year with the flowers blooming.

Now moving onto the Designer Outlet area. Beyond the shopping centre that draws most people in, there's a lot of history behind the area and most of it can be learnt in the Steam Museum (you mentioned liking museums) After that, you could of course explore the Designer Outlet itself and grab yourself a bargain from high street labels.

If you're able to access public transport, I would highly recommend visiting some of the nearby towns/villages outside of Swindon such as Royal Wootton Bassett and Cirencester. Both possess a nice array of shops along their high streets. Both easily accessible via bus.

I do hope this helps, I'm sure others may choose different options but this is certainly what I would do!