On the Lending page, use Check out equipment:
Kits: a kit is a named bundle, like "PA rig", that goes out in one checkout. Type a New kit name, tick the items and press Make the kit.
Someone outside the band: under To choose Someone outside the band… and fill in Outside borrower and Phone or email. They get no email. It's only written down so you can look it up, and players never see it.
GLAR won't let one piece of equipment go out to two people for overlapping dates. To take it back, open the item and press Mark returned.