To use the LeanXcale connection you just created, open the Alias tab and double-click over the connection name:

Then click the Connect button on the next screen:

You’ll see the SQuirreL interface and you can start typing SQL commands:

Change to the SQL tab, write the CREATE TABLE query and press Ctrl+Enter:

Change to the SQL tab, write the INSERT query and press Ctrl+Enter:

To see the tables in your schema and its details, go to the Objects tab, open your schema (USER1 in the image) and open the TABLE element of the tree. If you want to see information about a specific table, you can click in the table name (PERSONS in the image) and then in the tabs at the right. In the image, you can see that clicking over Columns gives you the list of columns of the table:

After clicking over the name of the table that you want to see its data, click on the Content tab to see the content you inserted in the table:

If you want to order the table data you’re viewing, you can click on the name of the column once to order in ascendant order or twice to order it in descendant order: