Hi! Please give me advice to study efficiently! (Coming from someone who study for too long)

I developed a habit of asking too many questions while studying a lesson. A single concept can turn into 2 hours (maybe more) of studying. I answer one question to another and read multiple research and journals until I get deeper and deeper to the topic, which caused me to barely or never finished the lesson at all.

So I decided to fix this habit by understanding the lesson on surface-level then entertained my questions and connect the concepts to each other after I finished understanding the lesson on surface-level.

But I still think that is not enough because I am about to enter college and I need to manage my time well.

So if any of you have any idea how to study more efficiently, please give me an advice. Thank you in advance for those people who will answer my question!