It’s the Wendover Woods 50. Organised by Centurion who put on quite a lot of the most popular U.K. ultras. It’s 5 10-mile loops of a pretty small but hilly wood. It’s 3000 metres / 10,000 ft in total of elevation gain.
Manchester to Liverpool looks good. I’ve considered that one as well as it runs right by my in-laws house along the trans-pennine way. Looks like a good first ultra to me!