Yeah, extract is boil only. If you're using extract and hops without steeped grains then you only have to worry about boil temperatures. If you're using steeped grain then you're entering into different territory with people who steep from cold to boiling, steep at 150º for 20 minutes... the list goes on and on.
If all you were given is extract and hops then just bring the water to a boil, remove from heat or turn off heat, add extract and stir to mix in, return to heat and bring to a boil and follow the hopping schedule.
It's pretty easy (with the right instructions) and fun to drink when you're all done!