named training learners" versus "training Concurrent learners" ?

Named training learners is an old licensing model that hasn't been used in years. So you only need to worry about Concurrent Learner licenses, if you need the Training module. Think of the Concurrent Learners license like a room full of chairs/desks. If you have a room with 50 licenses, then anyone who is enrolled in any training on your account can come in and take the training, but only 50 individuals can at one time. So the licenses are first come, first serve.

If you don't need to track individuals viewing objects, you should just distribute your content from within the Content library. You would just need to have Content Publisher/Author licenses to push content to the Content library, and there are no license limitations on accessing/viewing your content. You can even make content publicly viewable, so you don't have to deal with people needing a username and password to access your content.

If you just need to have a live meeting space for students to meet with an instructor, you should only need the Meeting Module, and you would most likely be looking at the Named Host licensing model, which allows you to name individuals (instructors most likely) that can create and run meetings that hold up to 100 individuals.

If you need more clarification on connect licensing (and don't feel bad if you do, it is complicated), you may want to take a few minutes to read our posting about what the Connect licensing options are and how they work: http://www.realeyes.com/blog/2012/04/17/adobe-connect-licensing/