So - checking your credit is a "soft pull" and cannot be seen by others and does not impact your credit score. However, allowing lenders to check your credit through a "hard pull" or inquiry does affect your credit.

Utilization only matters when you are trying to have your credit score look perfect for others to see. I never carry a balance, because that incurs interest, but I let a balance report every month unless I am applying for new credit. You should feel free to do whatever you want. But if you are going to apply for new credit, make sure the card is paid down BEFORE THE STATEMENT DATE.

In terms of making a purchase and letting it revolve, feel free to do so since its a 0% card. But only if you will be able to pay it off within the 14 months, and only if you aren't applying for new cards (as I mentioned above).

Congratulations on the new card! And welcome to the forums. Stick around to read and learn!