Do I need to clarify that I changed the mailing address? cuz this is my first time doing a CRA or tax return and I just moved in Feb and we need to call to unlock account

If this is you first time filing, then the CRA likely doesn't have your correct address, or other info on file. So, you will need to print and mail your return. Once you get your Notice of Assessment, then you will be able to create a CRA My Account login, and next year you can file online.