How to find out the percentage of contribution of a variable for another variable/feature?
To explicitly get the percentage of contribution for one variable to another feature, you can take their (pairwise Pearson) correlation and square it. That is the percentage of variation in one explained by variation in the other. (This is the R-squared of a linear regression, if you just regressed one variable on the other.)

Similarly, if you want to control for other factors (e.g. you want to control for day of the week), you can run a linear regression with just the control variables, then one with those control variables and another one of your predictors. The difference in adjusted R-squared between those models will be how much of the variation in Revenue is explained by the other predictor, beyond what's explained by your controls, and with a slight overfitting penalty for adding another variable.