As SeaJayPea indicates, nearly all insurance policies used to permit the holder to drive any other vehicle (not owned or hired by him, or driven for reward) with the minimal legal 'third party' cover. Many policies still do. (My 'third party, fire & theft' policy includes such cover). However several companies have now removed such cover from their policies (or, for example, limited it to drivers over 25 years of age). Nobody should ever assume that such cover exists, unless they've bothered to read the small print of their policy.
So you need to check the wording of your policy, but it seems likely that you'll find you weren't covered to drive your friend's car. (His policy would only cover you if you were a 'named driver' or if he'd got an 'any driver' policy for his car. Since such policies cost 'mega bucks', that would seem to be extremely unlikely).
If the matter had been dealt with by a fixed penalty notice, you would have had to pay £200 and would have received 6 penalty points on your licence.
Since the matter is to be brought before a court, you can receive between 6 and 8 points on your licence plus a fine. (Courts often seem to impose a fine of £200, to match that which would have been imposed by a fixed penalty notice, but lower fines - of, perhaps, £70 - are sometimes imposed upon people with low incomes. Similarly those people with higher incomes may face higher fines of up to £5000). Additionally you'll have to pay costs (of, perhaps, £80), plus a 'victim surcharge' of £15. A conviction before a court (unlike a fixed penalty notice) also creates, or adds to, a criminal record.
The law regards permitting someone to drive a car without insurance in the same way as actually doing so. So your friend can also be charged with an offence, and receive similar penalties.
Chris