1- Yes the course provides certification look at : https://linuxacademy.com/
2- Normaly it"s 19 per month , what i m offering is 3 months only for 10 $ ( and i have more than 5 invite links now )
3- You do not need to pay anything you only gonna pay me for the invite link then you sing up ( no credit card needed ) and you enjoy the ressources.
4- AWS Azure DevOps Linux OpenStack : are the available ressources on the academy , and you will be able the access all them courses
let me know