Learn to drive with either weekly driving lessons or an Intensive Driving Course.
On the motorway, you should not exceed the speed limit at any time. You should have an awareness of road signs and symbols (you can find these in the Highway Code) and have an understanding of how to safely overtake, for example, sticking to the left lane unless overtaking. When driving in the left lane, it's important that you move across for merging traffic from slip-roads - if it is safe to do so.