The folks above are right. Without seeing the plane or at least some pictures of what is going on it’s tough to give advice.
Start here: https://commonwoodworking.com/using-a-plough-plane/
Paul also has video, but we are only allowed one link
If you still have problems , the most likely issues are that the iron isn’t sticking out the right side of the shoe, assuming you know how to sharpen with a clearance angle. And start at the end of the grove and work back. Trying to take full length shavings is counterproductive. Wait until you are experienced to try that.
The overriding principle is that it is the FENCE , not the shoe that registers the cut. You can plane without the shoe touching the sides at all. You won’t have success if the side of the shoe binds. Sometimes a tapered wooden fence guide can be used to align the fence and shoe.
And as the irons get wider, you need to pay more attention to holding the plane vertically.