Hi everyone, my family recently adopted a 6-month old puppy. We adopted her from someone who was rehoming her, and unfortunately, the person wasn't very honest about her behavior. We have had dogs all our lives, and have gotten extremely lucky with no HUGE behavior issues before. We've had her for around 2 months now, and there are several issues. We have 3 cats, and she will chase them constantly. It's gotten to the point where she cannot be off her leash around them, and most of the time she is in a completely separate room from them. It's a big issue because our cats now mostly hide, and we cannot enjoy having Sophie (The puppy) around. She get's into a frenzy, and she absolutely HAS to chase the cat. It doesn't help that the cats run from her, but I can hardly blame them. It's similar with the other dogs in our home, she is always trying to play with them (they are elder dogs) and pretty much tramples them because she's bigger than them both. She's completely overbearing. She also doesn't listen to simple commands, which could be because she's so young. We're not at the point where we need to rehome her, and that would be our absolute last resort. Also, recently she has become possessive/slightly aggressive about the food bowl. We have another dog who is (slightly) possessive over food - and Sophie doesn't like sharing the food with her. Everything I find when I look up is either paying for professional training or complicated training regimens to do yourself. I have no experience in training dogs. I will definitely try my best if I need to, but I was hoping this forum could provide some insight/advice. Sorry for the long message! Thank you for any help.