I have just created 2 RECURRING TEMPLATES for the same customer. 1. How do I delete one of them? 2. And if I wont delete it will the customer be charged twice or not?

Let's take care of your recurring templates, userstorage123reg.

We can easily delete the duplicate recurring template through these steps:

1. Click the Gear icon in the upper-right corner and select Recurring transactions.
2. Look for the duplicate recurring template and click the drop-down arrow next to Edit.
3. Select Delete and click Yes to confirm the action.

If you don't want to delete the duplicate recurring template, we can assume some scenarios that will possibly happen. 

Do you want your customer to be charged twice with those recurring templates? If Yes, make sure you set each recurring template to Scheduled. If No, make sure the duplicate recurring template is set to Unscheduled or Reminder. Here's a link for reference: Create recurring transactions in QuickBooks Online.

If you have additional queries about the explanation I've come up, you can always get back on this thread so we can further help you. Have a great day!