Go for it - it will save you time when you get proficient and confident, give yourself plenty of time to 'practice' roadcraft/get to know the dimensions of the machine etc. before hitting the London peak traffic.
There's a fair few transferable skills you've got as a cyclist that are relevant - be plenty careful, as you say, if it's not for you, you can always back out.
Go for it - it will save you time when you get proficient and confident, give yourself plenty of time to 'practice' roadcraft/get to know the dimensions of the machine etc. before hitting the London peak traffic.
There's a fair few transferable skills you've got as a cyclist that are relevant - be plenty careful, as you say, if it's not for you, you can always back out.