Generally, for a sig like this I would recommend smaller text in a corner, preferably a generic font like Century Gothic [honestly, my favorite]
I would say you need to improve on making your render a part of your sig, maybe making them your main focal point and a little larger, as opposed to squashed to the side, because i really don't enjoy looking at a sig that's 80% background
Your lighting is ok, but could be improved
I would suggest reading some more tutorials
Keep at it! =)