As a mentee, it is up to you to outline your objectives with your mentor so that you can both get the most out of the relationship. Objectives can be both long term and short term and the best way to set your objectives is to think about what it is you want to achieve and by when.
You may have a very clear set of objectives in mind e.g. to be promoted within 12 months, but you may also be somewhat unsure about what exactly it is you want to achieve. It is important to be honest with yourself and your mentor, as they can help you define your objectives.
Over time your objectives may change, this is ok, but you must always discuss this with your mentor so that you can set new objectives and ensure that your relationship continues to develop.
Once you have set your objectives, you can get to work on achieving them. The best way to do this is to set Actions relating to these objectives in each meeting with your Mentor.