I’m at a loss at what I should do (pruning wise) for this bonsai.
It is not as simple as one size fits all. We/you need to know what you want from this bonsai.
Beginners are often happy with a small, skinny stick with some branches in a bonsai pot.
To achieve this sort of bonsai just prune the new shoots above a pair of leaves. We'd usually cut so each shoot has only 1 or 2 pairs of leaves left. see below.
Regular pruning and keeping the tree in a small pot slows growth dramatically so it's likely your tree will be pencil thick for the next 10-20 years if it survives that long. Need to be aware that it is difficult to keep small bonsai in small pots alive. Most of us have killed quite a few before working out all the necessary techniques.
More experienced bonsai growers aspire to develop a maple that looks more like a really old Japanese maple tree with thick trunk, bends and branches with plenty of twigs and leaves.
In this case, you can either grow as above and wait 30-40 years OR, as mentioned above, plant it into a larger pot or in the garden for 3-5 years to speed up growth. Then chop it back down to bonsai size and develop the branching. Still a 10-15 year project but worth the time and patience.
Looks like your bonsai came from Paradisia- Collectors Corner. If the stones are glued on (they seem to do that so they don't fall off while moving or handling the trees) you should break them up so you can check on soil moisture easier. It's likely your tree will need watering twice a day when the weather warms up through summer but always check soil moisture before deciding to water it. Constantly soggy soil is detrimental to roots and can sometimes kill a bonsai.
