Was it running fine before you put it away or did it have issues then?
Does it have a kill switch & is this working/have you remembered to fit the cord - I had a senior moment a few years ago & wasted a lot of time trying to find out why my auxiliary refused to start at the beginning of my first outing for that season
If it just splutter fuel everywhere then it sounds like it's flooding & I'd be having a look at the carb to check that the float is working as Dave suggested.
If the plug is soaking wet with fuel it's unlikely to start.
Have you checked for a spark?