An "Activity" in Ivo refers to the types of activities your organisation performs, such as Client Advocacy, Inquiries, Education/Group Sessions, Systemic Advocacy and so on.  It can also be thought of as the "services" your organisation provides.

The basic way to add a new activity to Ivo is through the "Create New Item" menu -

The first option, "Entity", creates an entity without any relationship to any other record in Ivo (although such a relationship can be established at a later time). 

The "File Note" item creates a file note from a completely blank form.

The remaining items are the various activities your organisation performs. They are all share the same basic components, such as contacts and file notes, so once you can work with one of these, you can work with all of them. One of the most commonly used activities is the "Client Advocacy Issue" -

On any form in Ivo, fields with a red star ( ) are mandatory.  On the left-hand side of the form is where you enter the name of the entity the record will be associated with.  For Client Advocacy Issues, this would be the client - that is, the person you are advocating on behalf of.  For Inquiries, it would generally be the caller, for Systemic Issues it might be your own organisation, and so on.  

To specify the entity, start by typing the name of the client.  Names of entities already in the system, that are a match for what you type, will be shown.  If the client is already in the system, simply click their name -

If you type the name of a client that is not in the system, Ivo will automatically switch to creating a new client (or entity) record -