The following exercises are single paradiddles phrased as 16th notes and executed around the drum set using the snare and three toms. (You can substitute any other drum or cymbal if you don’t have three toms.)
The sticking for all of these is R L R R – L R L L – R L R R – L R L L.
The next three involve crossovers. The notes marked with the (X) are notes where one arm crosses over the other to play the drum.
These are just a handful of examples of how you can come up with some melodic fills using paradiddles. Once you have a handle on these, come up with your own.
Here is a video of a paradiddle based groove.