If I’m understanding your question correctly, it sounds as if you don’t want to be overwhelmed by a whole huge bunch of vids on this subject all at once. You’d prefer to watch them a few at a time every few days.
By creating a playlist labeled, “Learning Java” you could then add all of the vids which your search turns up and watch them as slowly as you wish. Just keep moving down the list.
I think the only way you could get notifications of future vids on this same subject would be if you discover another YouTuber doing an ongoing teaching series on this.
You could then subscribe to his/her channel.
If you don’t find any folks doing a systematic ongoing series like that, then just do a new search every other week or so and add any not already in your your previously established playlist.
Another resource you could try would be to look at Podcasts (which are free) through the iTunes store. There are folks doing free podcast classes on a whole variety of topics.
And they don’t have the 10 minute time limit imposed like most of the YouTube stuff I’ve seen so far. Anyone can do a free podcast for whatever time period they choose afaik.
There is also a section called Itunes University (or something like that). I’d be really surprised if it didn’t have anything for learning Java.
And iTunes does have a notification system for podcasts to which you subscribe.