Why am I getting a 1 dollar charge ?for trying to purchase something with my card?

You are not getting a 1 dollar charge, what you are seeing is an authorization hold. See this Apple support article—>About payment card authorization holds from the App Store or iTunes Store - Apple Support

Apple may place an Authorization hold for $1.00 USD, on a newly added payment method to verify it can be charged. The authorization holds are reverted shortly after verification is completed.

See here: About payment card authorization holds from the App Store or iTunes Store - Apple Support

It may be a payment authorization hold which will be automatically reversed. See information in About payment card authorization holds from the App Store or iTunes Store - Apple Support

Isn't nice, when we all agree. 😉

We're either all correct or woefully mistaken. Either way, I'm in very good company.