Is travelling with 1 friend permitted in the UK now that the lockdown is enforced?

There is a lockdown in the UK.

I'm a student living at Warwickshire. I planned a 2 day trip a long time ago to the south of England, and I will be travelling by car with my friend (only 1 friend).

With the current lockdown rules, will I be stopped and fined?

What are the possible consequences?

Update: I'm not going anywhere! Thanks for the answers!