1) You have two options:
a) Open Manage | Database | relationships and find the relationship that defines this portal. Double Click the relationship line to open a dialog box where you can click the "allow creation of records via this relationship" check box for the portal's table. Now you can add new records in the portal just by entering data in the bottom blank row of the portal.
b) add a button on the layout that creates your new related button for you. This is often a better option if you enter enough data in your portal that you need to frequently scroll it to expose the bottm blank "add row" option a) adds to your portal:
Set Variable [$ID ; value: LayoutTable::PrimaryKey ]
Go To laout [//select layout based on portal's table here]
Set Field [PortalTable::foreignKey ; $ID ]
Go To Layout [original layout]
In portals with lots of records, this script is particularly useful if a sort order on the portal will sort this newly created record to the top of your portal.
2) The magnifying glass tells you that the field is searchable by quick search and green magnifying glass marked fields search faster than those with yellow magnifying glasses.