At this beginning stage you most likely have not been actually accepted as a student nor initiated in a formal or functional sense. It will generally be up to you, when you feel so inclined, to ask for either or both. Depending upon the situation and point of view and function of the teacher, he may make his acceptance as a student and initiation in a path at the same time or not. That will come and be dealt with as he sees fit. It is an important and far reaching step to take. And you will only be as sure as you can be that it is appropriate. Follow your own feeling and heart closely. If something does not feel right, then it is best to wait.
From the point of view of the teacher, this preliminary period - after you have been around for a while, attended outer classes and initial general instruction; and then also had an interview with him - is used, among other things, to determine if you will self-select to continue and how you will handle and react to both obstacles and possibilities placed in your way. This is in addition to any other work he may do. These and other outer functions will help him determine if you are ready to proceed, and how best to approach it. You need to remember that his goal is to assist you in your greater quest and goal to realize - actualize - your own being potential, and to assist you in becoming the productive, active, and aware embodiment that fulfills your point of being here. He is not interested in making you happy or feeling good - from a lower or personal point of view. He does not really care if you are blissful or high. He wants what is best for you and only wishes to assist you in being able to take that next step. That is enough.
The teacher will assess your actions and thoughts on an outer level. But more importantly, will put attention on and be aware of your needs, potentials, blocks, and path on an inner level; based upon his understanding, vision, and completeness of consciousness. It will be from this point of view, together with any assistance and/or guidance from the Hierarchy that will lead him to his next steps in dealing with you.
Should you both continue from here in parallel and converging paths, eventually you will come to the point of asking for initiation and acceptance as a student. The teacher may react immediately to your request or take any length of time he feels is right before responding. And in some cases, it may be he who starts this conversation in the first place, rather that waiting for you. The most important thing here is that he be clear if it is appropriate, and also how the timing should work out. He may use this as another means of assessment or "test" to see how true your intentions are, or for any other number of learning/teaching means. It is very important that he do what is "right" here.
The taking on of a student and initiation in a path is not done lightly. There are karmic implications in both. Just as for you, when there is an acceptance of the teacher, so too is there an acceptance by the teacher of you. He actually makes a connection to you and is present with you at all times thereafter - unless it is cut by him, by you through rejection, or by the hierarchy through intervention.
So too is initiation important, real, and active. Initiation is the beginning, as the word is defined. There is an actual link to the universal made, through the path and beings making up the "oversoul" of the group, or part of the way. This remains even though the link to a teacher may be severed. It also can be removed, altered, or enlarged or reduced, depending upon the greater needs in combination with your own true intentions and conscious function.
That is enough now said about these processes. The rest will come from your real interactions.