How do I view procedures or plates?

You can open them from several locations:

On the Maps tab, from the Plan sub-tab, in the displayed route, tap a SID or STAR “bubble”, then tap Plates.
From the top bar’s Search field, enter airport, tap Search, then tap the Plates button.
From the Airports (Apts) tab at the bottom, tap Procedures.
From the Procs (Procedures) tab at the bottom. Enter the airfield name in the Search field at the top.