Check to make sure there's not water in the mast. Have one person put his ear against the mast while the other picks up one end. If there's water inside, you'll hear it flowing past.
There are of course commerically available mast raising systems to assist you. Otherwise, if you can't raise the mast with two people, you definitely won't be able to do it alone. With two people, it should be a piece of cake. One person on either side of the mast. You both pick the mast up. Once the mast is up, one person holds it while the other person jumps down to connect the forestay.
You also need to consider that if you can't raise the mast with two people, you're probably not big enough or strong enough to right the boat in the event that you capsize. You would probably want to consider getting a righting aid or getting a smaller boat.
sm