Congratulations on taking the first big jump - getting a tree and asking for others ideas.
Going for simple the easiest style is a concentric clump.... look up John Glenangel on You tube... his videos on trunk chopping and pruning later are good for either a clump or the style below.
Personally I wouldn’t do a concentric clump on this guy, but you certainly could. This looks like the makings of a good Kabadachi style bonsai, with taller and shorter trunks! Sort of like this.
The basic plan for this style is
A. Choose a front and ensure each trunk can be clearly seen from the front. Remove trunks that impede this pattern.
B. Do differential cuts, with the larger trunks left longer, respective of their diameters and the same for the shorter. In other words the biggest diameter would be left the tallest....etc. Use the putty like cut paste and press it firmly down on each cut. The first one
@Pitoon suggests. It contains growth hormone.
C. Keep in half sun or use a 30-50% shade cloth until the new growth is well established.... be sure to water sparingly until robust foliage appears, but mist frequently. Do not prune any new foliage, including new sprouts from the base. You may use these later.
D. Wire one new long foliage branch upright for each trunk during the late fall or winter to establish the new trunk lines.
E. Start now to develop a wintering over plan!
OBTW - Do the cuts in the morning and ensure you take a half a dozen cuttings to grow out. This is a good practice for azaleas. You may need these for grafts. Also. Should your tree fail, you at least have new ones!
cheers
DSD sends