It might be a very good idea to invest in a level, they can be obtained for under $300, and once you learn how to use one, there will be absolutely no question about which piece of the framing is too high/low. Personally I use a rotating laser level, which sends out a rotating light beam at a constant elevation, so it is very quick and easy to determine the exact elevation of any point. You are going to need to do this throughout the construction process, for setting the foundation, setting the sills, setting the joists, major beams, second floor etc. My laser can also be used to determine if a structural element is plumb, although most of the time I use a carpenter's level for that. Can also be done with a plumb bob. Regardless of what you use, you absolutely need tools to level and plumb your framing and walls, and you need to know how to use them. Bad things happen when the structure is not level and plumb.