Some time late next week or maybe the week after I should be having my first AG brew day, I'll be using BIAB, and until I have it well in hand and I decide what I like in AG beers I'll be doing small batches 5 and10 litres. Not too much to pour away if I screw up

What I want is recommendations as to what types of grains and hops I should get, Maris Otter is an obvious choice but what else do I need to give me flexibility so I can do a range of types?
I'm especially thinking of hops cause they are relatively expensive and come in packs and but making small batches I probably won't be able to use a whole pack. So I need to be able to use whatever I buy in a range of beers/stouts /lagers.
Please chip in I don't want to spend a fortune to find that half the hops are never used.
I really appreciate your suggestions and help.
Many thanks. Aamcle