The best way to get your hands on any new activity is through hand on. You need to get out and get going. Starting from the first lessons on jargons used in the tutorials. If it is an equipment get to know what it is called and what the parts of it are.
If it is something like learning music, knowing its variants, and what you are interested in and so on. In sailing, you need to go and do your basic vocabulary building first. Once you know the language that sailors speak, you are ready to understand the lessons well. To enable communication between yourself and your crew, you need to know the vocabulary first. Even if you are just on a crewed charter and all you need to do is enjoy, a basic communication is a must.
Now, the part comes where you can get hands on. So, assuming you are a newbie and you have hired a skippered charter with a seasoned captain on board for a sailing holiday in Greece you can find yourself a role first. Even if the sailing trip is for pure enjoyment, learning how to navigate yourself and knowing your role on board and positioning yourself is good, to begin with. In fact, you can start it when you are completely at your will and nothing more than a passenger. Knowing what roles are offered onboard the vessel is a sure thing to learn here. In future, you would like to fit yourself into one of these or do all yourself.
What is the next step?
The next step is obviously to learn more about the position you like. Speaking more with everyone around and learning a thing or two about the vessel, about navigation, about what they do and how easy or difficult is it? This can also be done more officially.
Here is what you have to do to get hands on. Try to help as an extra crew and hand things when needed to the crew members. It is important to note that no amount of videos and manuals can make you fit as a sailor. So, learn as an extra and follow what they do and carefully observe everything. Try helping with things around. Ask questions, a lot of questions and understand the basics. There can never be a lot of information or training and every bit counts as much as you find.
To be able to sail independently in the future, you must understand that sailing is a pure joy and also a thing to respect. Being around the waters is a peaceful thing and can also turn into a nightmare for inexperienced people. So, even if you are there for a day or two and solely want to spend time in fun and frolic, a little time contributed to learn and help others around can be quite rewarding.
This is taking into consideration that you are eager to get into sailing as a hobby sometime in future or just trying to get hands on the stuff to know it better.