You need a pole
I see you’re not getting any help!
It looks like the J24 sail is about 3 feet taller and 4 feet wider than the standard Catalina 22 sail and over 25% larger in square footage, so be careful with the wind conditions!
I use a Macgregor 25 sail which is the same in height as the 22 but is 4 feet wider like yours. I use the standard Catalina fixed 8 foot pole and I do not seam to have any problems flying this overside sail. Before I added turning blocks to the stern, I fed the sheets through the hole in the mooring cleats at the stern. Because I only use the sail in light air I noticed no problems with using the cleats for the sheets. If you’re using this sail often then I would add turning blocks to eliminate chafe on the sheets from the cleats.
You’ll need a “pole mast eye” attached to the front of the mast at about the height of your boom or an eye with a track for adjusting it’s height.
You need a pole.
Now, you need someway of lifting and downhauling the spinnaker pole. In light air the weight of the pole will stretch the leech of the sail down so the sail will not fill with air properly, so lifting the sail end of the pole to different heights is a must. The opposite happens when the wind picks up a little, the sail will fill with so much air the pole will lift up so high the front side of clew will flip up and overlap the back of the sail collapsing it. These two lines need to be lead aft into the cockpit for instant adjustment as the wind velocity changes.
I used to feed the toping lift through one of the cleats at the base of the mast and the downhaul through the hole in one of the bow cleats. I then made a clip on bridle from cleat to cleat at deck level with a block for turning the downhaul back to the cockpit.
Because I do not race and my spinnaker, like yours is oversize and illegal, I removed the bridles from the pole and clip the above lines to the end of the pole, those bridles where always in the way when the pole was not being used which was 99% of the time.
Min. needed;
2 sheets about 50 feet long.
Mast eye
some kind of a broomstick pole at least 8 feet long with closing hooks at each end
extra long toping lift line capable of reaching the cockpit.
downhaul line capable of reaching the cockpit
add additional equipment after you figure out how it all works!