You don’t have to worry about it. Manager takes care of figuring out which accounts to debit and credit based on the transaction type and the account you enter. That’s one of its nice features. Only for the few transactions where you must make a journal entry do you have to really know about debits and credits.
In the case of your Spend money transaction, Manager will debit your Utilities expense account (or whatever you call it) and credit your Checking account (or whatever you named it). You will see this effect in the Summary if you delete and re-enter the transaction.
Since you are evidently new to Manager, I recommend spending some time with the Guides. In particular, read about creating a test business to learn the program.