I am currently building my first plane from plans,and was wondering if it is absolutely necessary to use a incidence meter to set my wing and stab,or if there is a alternative way of doing this,since i dont have a meter,thanks and merry x-mass

Hopefully your plans have a thrust line on them. Draw a line on the plans and then use a compass or protractor to find the angle on the plans then transfer it to the side of the fuselage. be careful depending on what type of plane the incidence is small. About three degrees on a trainer type plane to about a quarter degree on a pattern type plane.
Good Luck