Thanks for your quick answer!
I still have a problem when trying to figure out how to calculate the rise from the different elevation values of the points.
Is there a quick way to calculate the elevation difference between start- and endpoints?
I've joined the Sample table with the vertices shapefile so far.
Also, once I'm done with that, do i calculate the slope values with the field calculator in the attribute table? I've tried using the Raster calculator, but that one won't accept anything besides raster files (hence the name of the tool i guess)