Q.I’m in South Georgia and I planted a kumquat tree 2 yrs ago. It’s finally showing fruit and now they are falling off before th
ey are ripe. I use fertilizer sticks as recommended by garden center. Any advice as to what I could do to prevent this or use a di fferent fertilizer?

I don't think the fertilizer sticks are adequate, they don't provide a full range of nutrients. Switch to a more complete organic fertilizer product like this:
https://www.downtoearthfertilizer.com/products/blended_fertilizer/citrus-mix-6-3-3/
or this:
https://www.domyown.com/dr-earth-organic-all-purpose-fertilizer-p-9485.html
Work the fertilizer lightly into the soil surface and then mulch with an organic compost material.
Deep water after applying fertilizer, and be sure to water adequately, deeply - about once a week, not daily or several times a week, citrus can get root rot if overwatered. Water the entire root zone under the foliar canopy, not just next to the tree trunk.
The white spots on the leaves are hard to distinguish, but may be an insect pest.
For one plant you don't need a lot of insecticide, so you can buy a "ready to use" spray bottle like this:
https://www.domyown.com/monterey-houseplant-insect-spray-p-11260.html
or organic program alternative:
https://www.domyown.com/bonide-insecticidal-soap-rtu-p-1667.html