These videos are free and are good for start:
This is a comprehensive list of nifi tutorials: https://github.com/jfrazee/awesome-nifi
Nifi docs is also a good source: https://nifi.apache.org/docs.html
If you are looking for beginners' course: https://www.udemy.com/apache-nifi/
Hi @imran sk
One option is to download the free e-book "Apache NiFi for Dummies":
You can check my YouTube playlist. I have created it, especially for beginners.
NiFi the Complete Guide
After finishing my YouTube tutorial, if you wish to dive deep into the advanced topic, you can opt my Udemy course.
Apache NiFi - The Complete Guide (Udemy Course)
You can learn the same course in Skillshare for FREE using the below referral link.
Apache NiFi - The Complete Guide (Skillshare Course)
Here is a link of 5.5 hours of free Apache NiFi course.