assuming we know nothing about our opponent and this is the first hand we are playing against them, I would fold almost everything due to a lack of information on my opponent. I would probably call with QQ+ but that is about it. With no information on the opponent it seems like a gamble to call an all-in like this because of the extremely bad pot-odds.
for example, lets assume our opponent open shoves $10 (all-in) in a $0.05/$0.10 game online. we are in the big blind and it folds to us and we have AKs. If they have a random hand, our equity is 67% so it is a good call. Unfortunately, most sane opponents would not open shove 100bb with a random hand. say we are up against a range like AQo+ JJ+ our equity lowers to 52.53%. our equity is even lower if we are up against a super premium range like QQ+ (34.59% equity).
With no information on our opponent, we are essentially guessing that they would shove with non-premium hands. In my opinion, it would be better to fold everything except for QQ+ (with QQ being borderline) and gather some more information on the opponent so that we can make more informed decisions in the future. A fold is very cheap but making a bad call is not.