The Sanden compressor does not have a sump. The oil that is in the compressor when you first install it will get dispersed and circulated around the AC system the very moment you first kick on the compressor, so don't expect a specific oil level in the compressor at this point. The dip stick is pretty much useless. The lubrication of the compressor comes from the oil that is carried with the refrigerant as it circulates around the AC system and enters/exits the compressor. (The ideal oil circulation ratio is 3% by weight - fyi - but none of that really matters here.) So the compressor sees a steady and continuous supply of cooled oil.
If you unscrew the oil plug on the compressor you will blow the entire refrigerant charge. Don't do it. The oil will make a mess in your engine compartment, maybe even your entire garage and you may get frost-bite from exposure to the refrigerant. Freon is not poisonous but it is odorless; the danger comes in if it displaces the air that you breath in a small confined space.
So, back to basics: Check your pressures with refrigeration gauges; look for/fix leaks; evacuate the system and fill the recommended amount. I am not going to elaborate on this part - there should be plenty of youtube videos that walk you through this. Good luck!