You don’t need to master the Level 1 (absolute beginner) material before moving up to Level 2 (intermediate). It’s best to move up to level 2 as soon as possible, even before it feels comfortable.
The Bible, Breviary, and Catechism of Trent provide a huge amount of good material that is mostly intermediate, not advanced. You can keep busy with them for a long time.
pdf-P is a digitized pdf made from a printed book
pdf-T is a pdf generated from a text document
If the “web” location has a downloadable pdf-P, a separate link is usually not posted here.
LingQ is a huge help at the beginner and intermediate levels, and is free to use with limited functionality. More info on LingQ.
There is no plan to make audios or LingQ courses for level 3 content. If a pdf-T is available, you can import that into LingQ as your own private course.
These books aren’t as well suited to the extensive reading method of learning, but they are worth mentioning. If you like something here and it helps you make progress, that’s great.
Fr. William Most, Latin by the Natural Method (3 volumes)