A high carb breakfast is a good start. Try and get some protein in there too. Youve gone all night and your muscles need it.
In what way are you lifting the weights, doesnt sound like you know what your doing so it could be having a detrimental effect for now until you gain some more knowledge.
Boxing gyms tend not to advertise as heavily as martial arts gyms and such, so try walking around, you may be surprised and spot one randomly.

Try jogging now and then, maybe in the mornings. Something easy for now but itll get your body ready for when you join a gym.