Hate to say this but that’s not going to do much, it’s preferable to have the bottom open to bare soil. Then the worms can crawl in, you need to chop that up, the smaller the bits, the quicker it will compost.Our compost is ready in two monther from Spring to autumn.put a couple of shovels full of soil from your garden, that has the bacteria’s in that will get it working.Add green grass clippings, any junk mail and cardboard boxes you have, torn up. Tea leaves, coffee grounds, dead heads from plants, chopped twigs, a chipper is good if you have one. Try to aim for near enough equal green stuff and brown stuff.Have at at least two bins, a metre cube is a good size, fill one, then upside down it into the other one, cover both with a piece of carpet to keep the warmth in, in the half made one, also cover with some sheets of corregated iron/metal. When the original one is full, empty the first one you made into another container, darlek type or builders bags, and off you go, that’s the cycle. Keep it turned about, once a week is what we do, that gets air in and mixes everything together, also that will deter rats from nesting in it. We used all ours last autumn and we now have another lot ready to go this year, enough to cover the whole garden. Good luck, it’s very satisfying to make that lovely black gold.😀
if you stick with your design, then I suggest nailing a baton over the top so that it does not splay. Is the wood water and rot proof? You could line it? No ply or MDF as it will buckle and dissolve.
There are thousands of great 'how to...' vids on Youtube. They will tell you about the balance of greens and browns. Roughly half fresh green (veg, prunings, grass), half brown (newspaper, hay, shredded leaves, cardboard). Mix them, check it's not sloppy nor cracklingly dry, and wait. If it's in balance, then the more you check it and turn it over, the quicker it will turn to soil. The bigger the bin/pile, the hotter and quicker it can be.