Hot water (steam?) gas boiler not engaging burners, low pressure, sight glass full
If this steam boiler has not been serviced in a while I would recommend that you have this done to insure safe operation this winter. Using this boiler with too little or too much water in it can damage it and can be very dangerous. Without knowing more about how the boiler is connected into the heating system and what type steam system it is, it is hard for anyone to give a further explanation of how to fix your problem. I can say however that some of the return piping looks wrong. It does not have a "Hartford loop" in the the return at the boiler.  That doesn't mean that it will not work and heat your place. Also, post a picture of a typical radiator or baseboard installed in your home so the piping in and out can be seen. Also, send a picture of the return piping that can be seen in the next to last picture or the one before the radiator so I can see how the return is piped. One last thing, the piping that is connected to the pressure control and the low water cut out needs to be removed and cleaned. They both could keep the boiler from firing.