The most efficient way to learn a target language (ASL) is to immerse in a Deaf/ASL community. Fortunately, it doesn't require you to fly to another country to learn its language. There is a Deaf/ASL community in virtually every city in North America.
There are several ways you can immerse in learning ASL in natural environments.
Join an organization, a bilingual school, or a club of the Deaf/ASL people to volunteer in some various activities and events.
Some organizations of the Deaf/ASL provide this annual ASL Immersion Week program during each summer or some weekends.
Attend ASL social events, befriend with ASL/Ameslan people (be genuine in friendship with them first, not for solely learning ASL), and/or hang out with them.
Sitting and listening may be not much of a two-way interaction. But, there is still going on in an natural environment, not in a classroom. And, socialize afterward.
Listen to a presenter talking in ASL. If there is a voice interpreter provided, take an opportunity to watch ASL and how it is interpreted into English and vice versa. Also, turn off your ears to focus solely on ASL receptive skills. Use both methods alternatively to your comfort.
ASL vlogs are uncountable on YouTube.com. Look for the ones whose ASL is their first language. They are from all walks of life. Some sign fast, some are relaxing. Avoid ones who vocally speak, which indicates that the language they use is not authentic.
benefits of no voice policy in learning sign language.