Hi there Alice
Golly theres a lot of info in this dream or at least its a little erratic (Up and Down), Overall I get the sense your quite a grounded person but you will be more able to determine this, do you feel grounded in your life, or do you tend to have ideas which are quite imaginative but sometimes have trouble bringing them to fruition or concretising them.
Overall I get the impression that your dream speaks about how you manage your energy and what lessons you are learning right now, lessons involving your own personal growth and development, The various floors on which you choose to visit and take classes seems to allude to what particular aspects of consciousness you are developing within self. Our external situations, experiences and relationships tend to be the catalysts for growth and development within our SELF when we move through particular lessons and integrate them we grow from them.
Our energy system as a whole defines who we are or rather animates us in a way so that our total self expression is a reflection of the harmony or disharmony that our energy system expresses at any one time. This is difficult to word because it is not so much a concept of the mind but more an intuitive reality. Our energy system can be likened to a prism, when light is passed through it is reflected into 7 wavelengths that make up the light the light being a meataphor for our soul or pure consciousness. These 7 divisions and the varying degrees to which they are expressed interweave and blend to give us the dynamic expression of a person at any one time, the flow of light or energy being dependant on how we allow this energy to express itself. These seven centres are also referred to as chakras and theres a lot of reading out there if you want to explore this further.
I get the impression that the second floor in your dream is referring to the the sacral chakra. The sacral chakra consciousness is about relationships, the relationship we have with ourselves, which is ultimately reflected in the relationship we have with others. When the energy in this chakra flows freely we ourselves adapt to life in a fluid way spontaneous in our expression of creativity, and expressing a sense of ease in our relationships with ourselves, others and our sexuality.
It is also the chakra of duality where the masculine and feminine energy within our consciousness merges, when in harmony the outward manifestation of this chakra reflects itself in a harmonious relationship that we will attract into our lives, a marriage and sexual union are often both potent symbols of this sense of harmony. Disharmony occurs when we internalise the negative messages from those around us which undermine us and adversely affect the way we relate to ourselves and others.
When making choices 'masculine' that HONOUR our feelings 'feminine' this coupling is reflected energetically at the level of the sacral chakra we come more into relationship with ourselves, as a consequence issues are cleared at the sacral chakra allowing for a freer flow of energy through our system the energy of the sacral chakra nourishs our lower physical spine the lumbar area and our reproductive system. The sacral is also the wellsppring of our creative energy its where we give birth to ideas and creative notions our ability to act and transform our creative energy into art, dance, writing and any other from of creative expression reflects a healthy sacral chakra. Writers block will often impact on this area (as well as the throat chakra) in much the same way as any form of judgement we have about how we express ourselves or our ability to express ourselves.
Im just wandering if it is on this level that there is a lesson to learn at least your dream brings to your attention of what is happening at this level something you are not aware of or did not know existed. The Gym can be a place where you exercise a particular muscle or develop strength in an area, there is a lot happening on this level for you, the 'exercising' of your creativity happens here - whether there is a pay off for you in some way is up for you to decide. Your dream next seems to comment on how you relate to this inside of you there is a label or association you attach which is 'popular' quite often we hold certain notions of what it is to be cool or uncool what is liked or disliked and that which we believe to be liked we tend to develop in self and that which is disliked we hide, this may be part of your pay off and part of your pattern as it is being shown to you something maybe you have not considered before as it is this floor you were previously unaware of, again for you to decide. Your next port of call is the fourth floor this is the level of the heart when we are in this centre and balanced we are able to respond with unconditional love and an open heart, there is no judgement here and this is where your lesson resides or your learning is too take place, to develop within compassion and unconditional love and stability.
The up down nature of what is happening seems to imply that you are missing this lesson and jumping from the second to the sixth level there is a tendency it seems to stay in the mind rather than to come into your heart, and express from your heart this leaves one with a sense of being ungrounded and not secure 'the lift hanging in mid air', when we 'try' to express and create we stay locked in the mind particularly if there is an agenda, however when we express what comes to us and whats in our hearts it reflects who we really are. BTW these are just ideas and potentials of lessons you are engaging in at the moment and I am not assuming this is how it is for you but rather just throwing some ideas out there. Quite often these are lessons we all encounter in some way shape or form as well it helps us to clear issues at in the lower centres and enables us to live in a grounded fashion from our higher centres or more specifically the heart.
Just some ideas I hope it helps a little

Good Luck Malakeli