All of a project's setup is done from its “Settings” menu (gear icon in the project navigation bar). It is reserved for members with the “Can configure the project” right — the project creator and administrators have it automatically.

Settings page of a project with its tabs Stakeholders, Observations / Progress / Forms, CDE & naming scheme, Configurable categories, Priorities, Trash
The tabs of the Settings page.

Settings are grouped by tab:

In each list, the “Add” button creates an item, the pencil icon edits it and the bin icon deletes it. You can reorder items by dragging them: this order is the one shown everywhere in the app.

Tip: start with trades, then observation and form types, before inviting the team — members' rights are based on trades.