Being a bit more serious, it all depends on what sort of furniture floats your boat, the suitability of the timber, what material you can yield from it, what tools you have, how much money you got.
If you want something chunky, literally just carved out from the log, then unless you have chainsaw training then it’s going to be a case of hacking at it with chisels and saws etc. Freshly felled wood is very hard to cut with standard handsaws as the teeth tend to clog up.
It is however, easier generally to chip and chisel away at while it’s ‘green’ (wet).
You could take it to a sawmill who I’m sure would cut it up into boards for you for a small fee. You could then stack it with space between each board, covered from the rain in your garden for a year or two until it’s dry enough to use. Generally you should air-dry timber a year, per inch thickness.
If you are going to use it outside, then you don’t need to pay so much attention to the drying but alternative fixing methods to gluing etc may need to be found.
Also, what species is it? Some are more suitable for furniture use than others. I really ought to be better at identifying timber in that state in my job…but I’m not.
Personally, if you have limited tools and perhaps skills, I would keep it simple. Maybe get some other branches and sink them in underneath as short legs, and carve/chop/butcher out a sitting section or something…Make a bench of some type.
Post up your results.