Moberly is located on Streatham campus, but assuming you're asking how to get to center of campus (Forum building),
-Walk up Copplesotne Drive until you hit Clydesdale Road
-Turn right and walk down Cldyesdale Road
-Briefly turn right on to Streatham drive and then head up through the foot paths by Reed Hall
-Follow them through until you arrive on Queen's drive
-Head into Devonshire House, and walk through it until you arrive at the Forum
From the Forum you can navigate fairly easily to most places on campus, but depending on which building you need to get through this may not be the most straightforward route. I wouldn't really worry about hills, you're going to encounter them wherever you go in Exeter. I can recommend using Freshers Week to orient yourself around campus and find out where your lecture/seminar/lab rooms are. If you have any other questions, feel free to ask!