Need help creating an online store accepting all sort of Cryptos

Hello, before I lost too much time searching for an answer, I figured maybe some of you can help me.

I'm starting an online service business and I want to only accept cryptos. I have some knowledges on html, php, ajax and other web-related thing, but I'm having a hard time finding how to validate crypto transaction on website. Can someone show me where to look or explain how to implement this ?

Appreciate every bits of help