How can I enter projects if all my work is confidential?

You only need to enter as much information as you feel comfortable with. In most cases, a general description should be enough to convey the desired information without compromising confidentiality. You can find below a sample Project history with two projects described in general terms. No client or brand names are mentioned, no specific details provided, and yet a potential client can get the idea of the kind of projects you can deal with.