Judging from the picture, it is probably a sycamore. If the tree was dying, it's no surprise there were no seeds. Not sure how big that log is. From what I can see I'd say somewhere between 4" and 8".
If it's been cut into slices, then yes, take the bark off, seal the end grain and put them on a shelf somewhere dry and not too hot, best in a garage or a shed.
This is always a tricky size of tree. It's too small to really yield useful bowls (which are generally turned from side grain, not end grain) and it's too small to produce much in the way of useful spindle blanks (which should not have the pith anywhere in them). And yes, sycamores do tend to split heavily from the pith.
Best advice from my side would be: phone or email all tree surgeons within a suitable distance from you, there's bound to be one who would be happy to let you have decent size slabs from the trees he takes down for a small fee or even free of charge. All you need then is a couple of square metres of space somewhere in the garden, some concrete slabs, loads of stickers, and a tarpaulin, and you can over time build yourself a nice stack of wood.