For 2. Please refer to the Modus Quick start Guide which contains detailed steps on how to start a new PSoC 6 project: https://www.cypress.com/file/504366/download
For 1. In case of Modustoolbox you need to choose from a list of Board Support Packages (BSP) available for the cypress Kits. In case you are using a device that is not present in one of the kits then you need to start with the closest BSP and then build your own Custom BSP later.
In order to change the BSP you can click on Library Manager from the Quick panel > Tools and choose the new BSP.
Please refer ModustoolboxUser Guide for details on creating a custom BSP: https://www.cypress.com/file/504361/download