Pick a DataType and Suffix label to dynamically generate a name within the cockpit image below (text is selectable and copyable).
See enumerated descriptions below for more info. Suffix and entities details are described in BIDS glossary.
Entity requirements are also tabulated in adjacent BIDS entity table documentation.
Hints:
Hover your mouse over "Step 2" label options or "Step 3" entity text boxes to see the tooltip description.
The acquisition entity is free form (sans _ or -). Use it "to distinguish a different set of parameters used for acquiring the same modality". If that's too restrictive use the custom field for "any arbitrary comment which will not matter to how layout in BIDS"