Several robust, pre-made Excel sheets are available for free, saving significant design time.
Using the standard Hazen-Williams formula, the friction loss (meter head per 100 meters of pipe) can be computed via an Excel Add-In or with user-defined functions (VBA) that allow selective options for either Hazen-Williams or Darcy-Weisbach formulations.
Sum the total vertical lift. If you are pumping from a tank to a rooftop, it is the height difference between the two. ExcelCalcs Step 2: Calculate Friction Loss (Major Losses)
The most obvious number. You are lifting water against gravity.