[susan53]

It might have been better to start a new thread for this one as you've changed topic slightly and this is getting rather long. However :

1. Do the shopping : means for food, household stuff etc. Eg I'm going to the supermarket to do the shopping. What do you want for dinner tonight? / I forgot to get the milk when I did the shopping this morning / My husband and I always go to the supermarket on Saturday morning and do the shopping for the week.

2. Go shopping : Could be for food etc as above but could also be eg for clothes and other things : examples...
a) I forgot to get the milk when I went shopping this morning. I spent so long in the bookshop that it went right out of my head.
b) I went shopping in the centre of town yesterday and bought a new pair of trousers.

3. Go window shopping is quite different - it means to wander around the shops looking at things but without the intention of actually buying anything that day - possibly because you don't have enough money at the time, or because you want to look at things before deciding, or simply because you enjoy wandering round the shops. Eg I went window shopping in town this morning and saw a pair of trousers which I really liked. They were expensive though. I might go back and get them next week after I get paid. I'll think about it.