It is not possible to use
$select. In the $select, it is needed to specify all the columns you are need. I have tried to get items from following
"code": "-1, Microsoft.SharePoint.SPException",
"value": "The query to field 'LooKUp' is not valid. The $select query string must specify the target fields and the $expand query string must contains LooKUp."
Following end-point should give you all custom columns without expanding lookups
Above end-point will give you lookup column's
ID. If you need any information from this lookup column, the you have to make an another GET with this
ID. Following end-point can be used for getting lookup column's info.
/_api/web/lists/GetByTitle('listname')/GetItemById('lookup column id')