The first step is to buy bitcoin from a bitcoin exchange, see this article Where can I buy Bitcoin?
Once you have bitcoin in your exchange, you need to send the bitcoin to your BitPay wallet.
Download BitPay wallet App
Transfer Bitcoin from your Exchange to your BitPay wallet
Steps to follow:
Find and copy your BitPay wallet address. Example: “1CaC222sd23phL7ZKfFpRpd8W39XdsTTSF”
2. Select send bitcoin in your exchange and paste in your BitPay wallet address.
3. Enter the amount you want to transfer and send (double check everything always)
Move bitcoin from Coinbase to BitPay wallet
Find your BitPay wallet receiving address
With this address people can only send you money. It’s ok to share it.