You've gotten great advice here. Please, please neuter your boy, ASAP, before his tom cat behavior get's out of hand. The limited kill humane society I volunteer at has many community programs available including low or no cost spay/neuter and shots clinics. Please look in your county for something similar. I am a huge advocate for spay/neuter because at our county shelter, (not the one I volunteer at,) for every 1 dog that is put to sleep, 32 cats & kittens are also put to sleep. Overall, total euthanasia rate is 82% of all animals that come into this shelter and this is with a committed staff that does everything they can to get other rescues to take both the dogs and cats. Please, don't add to the pet population.
Also, it is in your best interest to set up an emergency fund, something you add to weekly. One late nite trip to the Evet can break your wallet for a year. If realistic finances at this time in your life makes this impossible, please reconsider if having any pet at this time in your life is the right thing.
And please, do not add another cat to your home until your boy is neutered, make sure the new addition is also spayed/neutered" before it comes in the house" and have the funds available to properly care for them in terms of feeding/litter/medical issues/shots and so forth.
Good luck and thank you for coming here to ask questions. While the answers may not always be what we want to hear, the folks here have both yours and your kitty's best interests at heart.