weekend in london- first timers

My cousin and i are booked into a hotel called the Crown Plaza London City in nov for a weekend.

We are celebrating our 30ths together. the First time for us t
o visit London! we are country girls.

We are driving to the hotel and leaving our car in the hotel carpark.
we want to visit the london eye and we have a show (mama Mia) booked for the satuarday night.

is there any recommedation that you have for us?
can we buy transport tickets in advance?
restartants recommdation?

we what to make the most of our weekend away!
sorry for the long report.

any hints for the trip are very much apperciated

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