Hi, I'm on the part of the tax return about changing the direct deposit details. Last year I did my tax with taxback, will the CRA have my bank details?

If you are not able to get into CRA My Account, then there are other ways that you can check/change your direct deposit information. This CRA page has a list: https://www.canada.ca/en/revenue-agency/services/about-canada-revenue-agency-cra/direct-deposit.html

If you are going to mail in your return, then you can include a copy of the direct deposit form with your tax return. You can download the form here: https://www.tpsgc-pwgsc.gc.ca/recgen/form/inscription-enrolment-eng.html

I need to inform the CRA about my new card

@Leonard Qamaniq  If you are going to pay your taxes owing by credit card, then you'll be able to enter the details of your current credit card when you get to that part of your return.