How can I improve my paper with mostly original contents and only two references?
Citations aren't just about avoiding plagiarism. They are more about embedding your work into a scientific context. Every paper should explain in an introduction section

why this work is relevant, and
how this work differs from previous approaches.

It is extremely rare that an approach is so novel that there is no meaningful prior work that can be referenced – many papers just apply an existing concept A to an  existing problem B and analyze whether this is useful, or extend an existing approach to have some desirable properties. If you can't reference such prior work, that is usually an indication that you don't understand the state of the art in your field. Such papers are unlikely to contribute to the field, and are very likely to be rejected by journals or conferences.
Most of the citations are usually in the introduction section of a paper, which is where related work is discussed. In contrast, it is somewhat normal that there are fewer references in the section where you describe your novel approach. You would still reference existing building blocks and methods of your approach. E.g. an experimental paper in CS might reference relevant software libraries that were used.
I am not an experienced author and know how hard it is to break into a field. It's difficult to get an overview of the state of the art in your field. However, this is a crucial part of writing a good paper – otherwise, it is quite likely that you're either doing something that has already been done, or that you're flaunting the methodological conventions of the field. For example, there might be existing testing methods or benchmark problems that every serious paper in that field should use. (If those existing methods were unsuitable, a paper about that could be useful as well!)