You can make use of Salesforce's Process Builder to create a process flow that will automatically create new Projects from Opportunities. This help article will walk you through how to configure this automation.
Start with the video below:
In this section, we are going to walk through adding a new field on the Opportunity object called "Project Auto Created" which will be a checkbox.
We are going to use this checkbox to indicate whether a project has already been created by the process flow. We are also going to configure the process flow to check this field to determine whether a new project should be created from the opportunity when the opportunity is edited. This prevents the process flow from creating a new project every time the opportunity record is edited.
In this section, we are going to go through how to create a process flow which will automatically create projects from Opportunities based on the criteria we specify.
Once the process flow is active, it will now auto create projects when the criteria you defined is met.