On my journey to take on the OSCP I learned that pivoting/tunneling can be a confusing concept at first for beginners. After doing extensive research I came across an awesome easy to use tool called Ligolo-ng. Ligolo-ng is a simple, lightweight and fast tool that allows pentesters to establish tunnels from a reverse TCP/TLS connection using a tun interface (without the need of SOCKS).
To follow this walkthrough or do some practicing I would recommend signing up with Hack The Box Pro labs. The pro labs have a lot of pivoting/tunneling involved that will help boost your comfort with these concepts and get you ready to take on the OSCP or real world pen tests.
Note: If you are a visual learner I would recommend this YouTube video I found very helpful :)