Adjusting dimmable lights

Just got my new light installed but have no idea where to adjust it to as I have no light meter may get one later to make this easier.

So im going to start off basically almost at full intensity at about the same height as I had my old light and work my way down hoping I dont do to much damage

Without a kill-a-watt meter it’s a guessing game. Turning the current all the way down will be about 55w and current all the way up is about 158w.