Apologies if you already know these things about driving in the UK.
Bus Lanes (Oxford loves 'em) - lanes (usually the one on the left) reserved for buses and taxis. Driving in one can get you a fine usually detected by cameras. You need to check the time each is in force: some are 24/7, some only certain days of the week and others only at certain times on certain days. if you're on a route with on-ff bus lanes, don't assume they'll all have the same time restrictions.
Roundabouts - lots on Oxford and the surrounding areas. Worth watching a few YouTube videos if you are not familiar with them
Speed limits - again familiarize yourself with the signs and the associated limit. I suspect central Oxford is now a 20mph zone although I haven't driven there for years (despite many visits) because parking is such a problem..
Navigation - get a good SatNav or be able to use Google maps on your internet package. Have the sound on, as this will help get you in the correct lane when approaching roundabouts. Postcodes - combination of letters and numbers at the end of every address - are very helpful in finding out of the way places. Note - some big attractions (Blenheim Palace, maybe) have a separate postcode for deliveries and visitors car park (yes, it really is big). Check you've got the right one. If you have a place to park in Oxford, the one way system is navigable (just about) but it is quite tortuous.
Finally, if driving at night or in the evening in central Oxford you may find lots of students on bikes. Safest to assume they've been drinking and will ignore red lights, Give Way signs etc I speak from personal experience, albeit nearly 50 years ago!