There is a better alternative to BitPay which is BTCPay Server.
It is not so known but I think that they provide a good service.
https://btcpayserver.org/
I've been running btcpayserver for quite a while now, however, btcpayserver =/= bitpay.
Bitpay is a thirth party payment processor. You create an account with them, read the doc's for their api, get some support, and you can start accepting payments with a very small learning curve, and in just a couple of hours. The downside is that they charge a fee and you do not controll the complete payment process.
Btcpayserver is a very elaborate script that allows you to act as your own payment processor. However, you need to run a full node and run several daemons in order to use btcpayserver. If you get btcpayserver up and running, you'll process your payments for free, and everything will be under your own controll, but if something goes wrong: you alone are responsible.
Don't get me wrong: i love btcpayserver, but for a newbie with not a lot of experience, the learning curve on how to get btcpayserver running *might* be to steep.