kind of a weird question, but why does one project have the venv part and the other doesn’t. Also, when I enter to check the folders of both projects, the one without venv has signifcantly less files within it.
Just as PyCharm indicates, your project2 contains a venv folder, whereas project3 doesn’t. This folder usually contains a virtual environment, that allows you to install an independent set of Python packages for your current project. Even newly created virtual environments contain more than a thousand files, hence the difference between your two projects.
PyCharm can automatically manage virtual environments, I assume you did check this option for project2 and not for project3. JetBrains provide documentation on how to manage virtual environments with PyCharm, you can find it here.