On one hand, you need to be able to ID repeat customers. A log book or journal is much more dangerous, in LE hands. I'd rather you deleted all the address book but would understand if you chose to keep first names & numbers.
On the other hand, I have my hobby phone & delete everything before I leave the location. If it falls into the wrong hands be it LE or a spouce... at least I did not make it easy. The annoyance is I must go to your web sire to get your phone to make the calls because theyt are deleted.
Probably texts & emails are the most dangerous. Delete at once since likely your laptop will be a your locatrion.
Don't keep records that are potentially incriminating... just don't. In most jurisdictions this is a petty crime. LE may gather any info that is laying arround but LE will not go to great lengths & expend a lot of energy unless someone is high profile or a more serious crime has been committed.