Multivariable linear regression is all about taking in a set of data points (x0, x1, …,xn, y) and to be able to predict y values for some other data points (x0',x1',…,xn'). I'm giving an example here on how to do so in Python as well as computing the coefficient of determination (R2) to see how well the predictor variables model y.
See the following link for an indepth look: