I believe I see what @PRR1950 was referring to, I'm having a little trouble seeing track joints. The longest run is up to that upper level siding. To avoid the "5 or 6 joint rule" the next two longest runs are to the middle of the front curves on the upper level. On both sides, the block would run from the opening, straight through the first set of switches (isolate the turnouts) back around to the next switch on either side. On the left that is the switch were your lower track meets the upper level, on the right it's the first switch facing the front. It looks like you can wire the front half of the lower section in similar locations. There is a block on the upper level on the right side that completes the loopback. So there's 5 blocks/connections and the front half is wired.
Is your opening hinged? If so you can wire it to the tracks on the hinge side with a terminal strip connection, like a jumper wire, and piggy back on the adjacent blocks. Not nearly as noisy as a track joint.