Add crm fields

Yes, you can add as many fields as you want to Contacts, Accounts, and Opportunities. You can also hide any of the standard fields that you are not needing to use. And yes, you can change the order of how the fields are displayed if that is what you are asking about when you say sortable.

In order to do all of this, when you log into the system, go to Settings and then Edit Layout and you will be able to make all of these changes.