Use it to measure out an extension, a garden path, or anything else that's really long. In other words, the sort of thing you don't have to measure very often. You don't want a 30m long tape measure hanging around your house just for that, so borrow ours for a week instead.
Do I need any experience?
No.
Is there anything I should bear in mind?
Please give the tape a wipe/dry if you've been using it outside.