Newbie here in need of help if possible please

Onto my second kit (first was an Admirals reserve, very nice) and opted for Coopers Dark Ale. Followed the kit instructions last night (used 1kg brewing sugar), temperatures were all ok (22 deg when I added the yeast) room temperature of 21 deg. Since adding the yeast last night not a huge amount has happened, no thick froth/crust like I got with my Admirals... kind of looks like its stalled, or am I being impatient? At time of writing its been in about 18 hours.... Should I be worrying/correcting anything?
Many thanks,
Baz