would i need a fuse when experimenting with transformers?
You don't need a fuse, but it is highly recommended. If you accidentally short out a winding then the current will be very high and the transformer could get damaged. A small transformer that draws low current is more vulnerable without a fuse, because the mains fuse or circuit breaker may not trip fast enough (if at all) to protect it.

Small transformers often have an embedded temperature fuse that blows if the windings overheat or short-circuit. This fuse cannot be replaced! Using an external fuse with the lowest rating you can get away with should prevent the internal fuse from blowing in a fault condition.     

A 1A fuse is fine for a transformer that is rated at 0.7 Amps. If you are just measuring output voltages with a meter then the operating current should be much lower - the fuse only needs a higher rating to survive the surge current at switch-on.