The first question is, what kind of tree are you envisioning as your final image. If you don't answer this question, you can waste a decade of work, with nothing to show for.
So, the question is, are you trying to create A) a young-looking, easily achievable, low quality bonsai (some call that a mallsai), or B) a high quality bonsai that creates the impression of great age and power?
This question is not a rhetorical one, and my intention is by no means to criticize the owner's taste or intentions. It has specific practical implications, and depending on your answer, it requires a completely different course of action. There is no right or wrong choice, it depends on what are you aiming for, and how much time do you want to devote to it.
If your intention is to go with plan A, then you just re-pot the tree into a good quality soil, clean up the nebari (which you did), and start working with the branches, by pruning and wiring them (a quick look at your tree reveals that the lower trunk displays the morphology of the tuberous roots, a standard feature of this species. It makes the tree look juvenile).
If, however, you want to pursue plan B, then you need to forget about the bonsai pot, and forget about any shaping or styling of the branches. In that case, the only things you need to work on, for the next 5 - 7 years, is the nebari and the trunk line. Everything else is irrelevant.
There are simple techniques to build powerful nebari, but there is no point in going into details, since you may not want to go that route. Remember, that with broadleaf trees, you either build nebari and trunk, or you build branches. You cannot do both in the same time. With conifers, you need to do both at the same time, due to the fact that they don't bud from old wood.
Also, remember, that as we learn more and more about bonsai, our taste and goals will drastically change with time. At first, we are easily impressed by a half-decent mallsai. Later, this all changes. If possible, we want to avoid the scenario where we aim for something that later will mean nothing to us. But I am not sure that this can be avoided at all. It may be that some mistakes are absolutely necessary to be made since that is part of learning.