There are two types of pipelines in Jenkins:
Declarative and Scripted Pipelines are totally different in their construction. Declarative Pipeline is a more recent feature of Jenkins Pipeline that provides better syntactical features compared to Scripted Pipeline syntax. Declarative allows us to write and read the Pipeline code better.
If you want to learn Jenkins, you can register for this Jenkins Training course by Intellipaat.
Also, watch this video on Jenkins Pipeline Tutorial: