The first loan does not require you to catalog everything you own. It requires one record for the thing that is leaving.
Tap + to add a loan
From the Loan It loan list, tap the + button.
The Add Loan screen opens with the borrowed date set to today. If you have configured an automatic default due date in Settings, that can be filled in as well.
Describe the item
Enter the item in Description. This is the required field.
Write enough that you will recognize the object later: Cordless drill with black case is more useful than tool, and The Left Hand of Darkness — Le Guin is more useful than book.
If the item is a book, the Book Barcode action can scan an ISBN and use available Open Library metadata to help fill the description. You can also simply type it.
Add the borrower if you know who has it
The Borrower field is optional.
Type a name, or tap the contact icon to choose a person with Android's contact picker. Loan It can store the selected name without requiring you to grant access to the full address book.
A loan without a borrower can still be saved, but if the whole purpose of the record is “who has this?”, the name is usually worth the few seconds.
Add a due date or photo only if they help
The borrowed date can be changed if you are entering an older loan. A due date is optional.
You can also add a photo from the gallery or camera. For an ordinary object, one photo can preserve details that are tedious to describe: which cable was included, which edition you lent, or the condition of the item when it left.
Leave Returned blank for something that is still out.
Tap Save
Tap Save when the description and any useful optional details are in place.
The record can then be searched and viewed with your other loans. When the item comes back, mark it returned rather than deleting the record; that preserves the lending history.
That is enough for a first loan. The system becomes useful because the record exists before memory has to do the work.
The tool used in this workflow
Loan It
Loan It keeps local records of physical things you lend, including item description, borrower, dates, and photos. It can also scan book ISBNs, filter outstanding and overdue loans, preserve borrower history, and mark items returned.