if i buy level 3 of construction will my builders become master builders becaue i cant get them to become master builders...if thats not the answer....how do i make them become master builders?

The only way that any villager can master a skill is by working at that job. If you need a master builder, you need to have them work at construction-related jobs. The Village Tech levels allow the villagers to do new things, but they don't affect the villagers' skill levels.

What do i do that gets them to become master builders....theres nothing to build...i continuously get them to fix the huts but thats not working....ANYTHING PLEASE

If you haven't bought Level 3 of Construction, doing so would give your builders something new to work on. That would help them raise their skill level.