Dog reactive

Hello! This is my first time posting in this sub. I adopted a poodle a month ago from a rescue. She was being rehomed bc she started fighting with the other dog in the house after her previous owners had moved. From my understanding she could have killed the other dog. She’s now living with me by herself, but she’s aggressive towards other dogs and certain people. She’s had full vet checkups to rule out anything physically, and she’s a very sweet and docile dog towards my mother and I, but it’s clear she’s learned some bad habits, and I’m not sure how the trainer she was sent to before I got her trained her, so I’m posting here to figure out how I can mitigate any dog/dog interactions with the least amount of stress and excitement.

Background: female standard poodle, 2 years old, spayed at 18 months. Sent away for training after first dangerous encounter with previous owners dog.

She knows sit and stay, and has a space she goes in (not crate trained, previous family didn’t like using it, she really hates it)

Very food motivated, but also stubborn. It’s clear that she was trained in a way I haven t deciphered yet.

Had one unplanned interaction with an off leash dog at her groomer which went poorly (neighbors dog ran over and got in her face, had to get between them as the strange dog was pushy and also aggressive.)

I grew up with dogs, but all those dogs were puppies when we got them, and they weren’t dog reactive like she is.

Any tips would be very helpful. Thanks!