For that, you need to use Visual Studio Code (and AL) for creating the dataset and the RDLC layout, then you can customizw the layout with standard tools like Report Builder.
regarding standard reports: actually you cannot modify a standard report. If you need that, you need to do:
1) From your local sandbox, export the standard report as TXT
2) Convert the TXT to AL with Txt2AL tool. This will give you a .al file (dataset) and .rdlc file (layout).
3) Import the AL files in VS Code and modify them as per your needs
4) Load the report in D365BC