Hello and welcome Gregolam,
First I wanted to say it's great to see your excitement with this dance coming across here in your posts. As Angel said, you obviously have a great attitude and the right mindset and I think you'll go far as a result.
You are getting great advice here. I'm no expert or teacher (some on here are), but I'll throw in a few things I think might be helpful. One thing I felt might be accidentally misleading in the above posts is this idea of sharing weight in a close embrace. Some close embrace styles literally share weight where the dancers would fall if they were not both there, but this is not the only close embrace. In my close embrace style I am on my own axis and my follower could leave without me falling - she feels my constant presence, and vice versa, through a connected forward pressure between our chests but we are each on our own axis, not sharing an axis. My weight is "forward", over my toes, but I am not leaning on her. So there are many different styles of embrace, all valid, and I'm not saying anything about which option is best. My point is simply that there can be a tendency for a beginner to hear "share weight" or "lean" and end up with an uncomfortable result where one dancer is carrying the other so you want to avoid that. I would slightly modify Mladenac's statement above - I would say "if your chests are not in contact, then you are not dancing close embrace, you are dancing in an open embrace"
You mentioned an "exaggerated lean" when you try to indicate your intention. I was once given an analogy that helped me, which was to think of the two dancers' spines, then move those spines around the dancefloor. So if you imagine that whatever the position of your spines before you step (depends on the embrace and level of shared axis), you would move your spine parralel to the floor without changing it's attitude. Thinking in this way helped me to move my upper body consistently without losing my posture or leaning as you describe.
Next thing I found that helped me was the idea of indicating a step and moving "leg first". So if you imagine that you want to lead a step to your left, your partners right, you would give a slight indication in that direction by moving your spine a little that way. When she picks up that indication, if she is skilled, her leg will go out ready to move as will yours but she will not move immediately. Then as you continue the movement of your spine the two of you will move together to find your new axis at the end of the step. In sending the legs out first, in a sense you are marking where you will go, but until you both move your axis, you can still change direction and adjust the movement. (this will be important later for all sorts of things because it allows you to "play" with her free leg - a simple example is to send the legs out then bring them back again in order to play with the rhythm of the music). The "indication" part can be extremely subtle with a skilled follower but with the ladies in your beginner class may have to be quite a noticeable movement. Note that the leg going out can be "balanced" by contraposture which you might need to work on or which might just come naturally to you - I often find the more I try to think about that the harder it gets.
Lastly on a "technical" note, just bear in mind that a step is a "continuum" and your indication will need to adapt to both the sensitivity of the follower and the size and speed of step you wish to lead. Beginner followers will need a lot more indication and beginner dancers will tend to simply step the same distance each time (whatever distance is their basic comfortable step). Down the line though you will be looking to convey in the indication for the step how far and how fast you want to move, and that indication will also have to adjust to the partner you're dancing with... but it may be too early to worry about that, I'm just being enthusiastic because you're so clearly keen.
Last of all, I would look around your dance community for a mentor among the better dancers. In my experience the ladies are very keen to encourage a new leader and very patient allowing you to lead them so you can get a good idea of what you're trying to achieve. Tell them how keen you are to get this right and that you don't want them to make allowances for you... if they follow what you are actually leading, you will soon find plenty to work on - I remember early on thinking a lady was absolutely mad because she was stepping all over the place - it turned out she was very skilled and every time I had a little beginner wobble she was following me
best wishes,
Blue
