I have never been to Oxford, despite many trips to London. I like college towns, such as Coimbra in Portugal and Princeton, NJ in the US.

if you can advise, as though I am 5 years old, how best to do this: train; bus; driver with details, I am appreciative.

and if you can advise what walking tour to book ahead, what not to miss, where to eat, I would also appreciate that.

From where in London? What time of year and roughly how long a day do you want? And any interest?

Fast trains and express buses. Couldn't be easier. Trains leave from either Paddington or Marlebone stations - Paddington is a slightly faster trip. And the bus - confusingly called the Oxford Tube leaves from Victoria Coach Station or Baker Street and is just a little bit slower.

We enjoyed a Sri Lankan meal at The Coconut Tree in Oxford!

Fixing typo