How Come I Lost 1 Dollar After I Registered With Paypal?

Hello
this is called “provision”
When you first add your credit card on paypal system, they have checked that you have entered a “real” credit card (to check if your credit card exists)
They have charged you $1 and they saw that your credit card is usable and there is no any problem.
It is not a “real charge” it is only a try. This is generally done between banks and merchants.
Normally, when you buy something with your credit card, your account balance reduces. For example, if you have $100 in your card, and you buy something that costs you $15, this $15 automatically reduces from your account balance when you press the “buy now” or “purchase” button.
Your bank does not immediately send this $15 to the merchant. It takes generally 1 week.
But when a merchant makes a provision, they charge you for $1 and see if your credit card exists. This is only for verification purposes and sometimes it is used to see if you have $50 $60 (or any else) in your credit card (to control you have the real ability to make a payment with your cc)
Because this is called a provision, your merchant DOES NOT WANT THIS MONEY from your bank. Because within 1 week (I dont know the exact day) your merchant does not request the processed money from your bank, this money AUTOMATICALLY CANCELS ITSELF.
simply:
dont worry. paypal charged you $1 but this was “not” a real transaction. It was a provision. You will probably see your $1 debited (or refunded, if you talk technically) in your credit card again in a few days.