A mate just went over seas and left me one of his windsurfer.. it dosent have a mast though and im not shore what size mast i need to get.. by the way i have to mention that iv never done this befor.
i have to sails

THE FIRST SAIL SAYS THE FOLLOWING
compatiblemast MCS 27.5 460cm 15'1''
boom slalom #B1 186 cm 6'1''
luff fixed 480cm 15'9''

and the other sail says...

5.3 cam1+1 luff: 444cm BOOM: 167cm
Preferred mast:
sailworks epoxy Lite 440
MCS mast Flex: 13-16%
MCS Mast Stiffness 23-25

CAN SOMEONE PLZ HELP .....

I would say a 460 for the first sail and possibly the second sail if the head can be extended.

Sounds like OLD gear.

How big is the board? If it doesn't have a size written on it it probably has a model name. Someone here will know the model. For learning big boards are better.

You would probably start by using the small sail. (the 5.3). It sounds like the ideal mast should be a 430/ IMCS 21 (IMCS has replaced MCS for stiffness specification. Its a little different but for a 430 IMCS = MCS x 0.86. For a 460 IMCS = MCS.). It should be a semi soft top. Neil Pryde, North, KA and Gun are brands that are like that. I would go and find a second hand Neil Pryde 430. Lighter is better but also more expensive. Don't spend heaps. You'll want to upgrade everything when the bug bites. Old stuff is cheap.

Do you have a set of booms?

Do you have a mast extension?

Do you have a mast foot? (the bit that fixes to the board)