I just learnt to ride a bike
so now need to buy one to practice so DS and I can go out together with the wind rushing through our hair and the pollution choking our lungs
Total novice and I've looked at so many bikes and listened to so many opinions that my head hurts...
I need:
Easy bike for a beginner for pootling around locally;
I'm told single speed bike is a bad idea unless I don't plan to get up any hills but have never changed gear on a bike so am thinking that 3-7 speed would be enough and not so scary;
Told that enclosed gears are easier than the gears that look like extra little wheels on the back wheel
;
I'm tall (5'9") so need a larger ladies bike;
Like the look of these www.dutchie.co.uk/Dutchie-Chic-Vintage-Ladies-Dutch-Bike.html but don't have £300+ to spare;
Happy to go for second hand
But the killer is my budget - ideally would like to pay £100 (ha ha ha) but would stretch up to £200 if necessary. I thought that sounded like a lot of money but it appears to be the bargain basement bucket of the bike world. 
Any advise from wise cycling MN'ers?