NJ Bob - welcome to the forum.
It sounds like you are trying a modified version of SFG.
I am a long time SFG enthusiast. In the beginning I thought I could skip steps and just use the intensive planting technique without really following Mel's guidelines.
With age, experience and hopefully some acquired wisdom I now follow Mel's plan much closer than I used to. Mel put many years into research and experimentation to come up with a perfect system. "If it ain't broke don't fix it."
Check out the web site.
Interior measurement of your boxes - 4' x 4' x 6"/8"
Spend the $ on commercial grade, woven landscape cloth to line your boxes with. The cheap stuff at big box stores is just that - cheap. You get what you pay for.
Use Mel's mix - a soil less mixture of 1/3 compost, 1/3 peat and 1/3 horticultural vermiculite. You will have a weed free garden.
Vertical gardening to maximize you space
Staggered planting dates to extend your growing season
Plant vegetables that are region specific at the correct time for your region
Get the book - there are 2 - 1st and 2nd editions. I have both. If you get one get the 2nd edition.
If you really want to garden start a compost bin (or 2). Check out the composting forum.
Since your box is started you can utilize what you have but do put the leaves back in - turned in - not just set on top. You will need to monitor your soil nitrogen level. Have a soil test done through your County Extension Office. WELL worth the money ($10 - $20).
Get the book, and start a second box. Use Mel's mix. I make my own but it is available on line. Compare the results. Nothing to lose and lots of knowledge and experience to gain.