reluctant
Not really wanting to do something, but maybe doing it.
Reluctant means unwilling or hesitant to do something. When you're reluctant, you don't refuse outright, but you drag your feet or need some convincing. A reluctant reader doesn't necessarily hate books but needs encouragement to pick one up. A reluctant volunteer might agree to help clean up after the party, but only after friends ask several times.
The word captures that in-between feeling: not an absolute “no,” but definitely not an enthusiastic “yes!” You might be reluctant to jump off the high dive even though you know how to swim, or reluctant to try a new food even though everyone says it's delicious.
Notice that being reluctant isn't the same as being lazy or stubborn. Sometimes reluctance comes from nervousness, doubt, or simply preferring to do something else. A student might be a reluctant public speaker because they get nervous, not because they're unwilling to work hard. When someone does something reluctantly, they do it anyway, but without enthusiasm or eagerness. The opposite would be doing something eagerly or willingly.