The main aim of the freestyle project is implementing, developing, or running simple jobs such as enabling you to specify the version control system from where you need to extract code and build it and call tests. Freestyle projects are for orchestration simple jobs for a project.
Pipeline Project is better either to set up a CD pipeline or to define the deployment pipeline as code. The pipeline project is suitable to build pipelines for complex jobs whereas the freestyle project is suitable for simple jobs.
If you want to learn Jenkins, check out this Jenkins Course by Intellipaat.
Also, watch this video on Jenkins Pipeline: