New rescue - am I doing this right?

Hi all,

I recently adopted (about a week ago) a chihuahua mix who's about 1 year old and has already had puppies. Overall, she's has a pretty calm temperament(sans major distractions). She's bonded quickly with me, follows me and listens a majority of the time. So far, she's learned that she can't jump on me for attention and sits instead. She's also quickly getting the hang of sitting before she gets a leash on or goes through a door. Inside my apartment, she basically has sit, stay, and come figured out. She is obviously a very intelligent dog and probably got some prior training, especially since this is the progress after a week.

But there's some behaviors I want to nip in the bud while she's still getting used to my apartment and learning what is and isn't ok. When she's in the living room, she barks and has the hairs on her back stand up on her back when anyone passes our door or leaves their apartment. This stops when she's in the bedroom(I'm assuming because she's removed from the stimulus). If anyone knocks at the door, she goes bonkers again with the barking and hairs on her back. I know yelling at her won't help since it just raises the intensity of the moment. When people pass, I'm making an effort to ignore her until she's calm and sits down then give a reward (but I don't know if this will just confuse her into thinking it's ok to bark). There's some confusing info out there that says either ignore completely until they're quiet or to use the hush/quiet command to get them to quiet on command. If anyone has had success reducing or removing this behavior, I'm welcome to any advice.

The second behavior is on walks. She gets nervous of all the people and cars since I'm on a college campus. I'm currently going to quiet areas with little distractions and attempting to work with settling, similar to how I got her to automatically sit before getting attention. This has reduced the nervousness on walks some as long as the walks aren't too long. Instead, she now barks(not rapid and incessantly, but only a few barks) when she sees a group of people. I'm not sure if this is appropriate barking as a hello or if she's nervous and saying "stay back." The hairs on her back don't go up here but I can tell other people respond a bit fearfully.

Overall, I'm fearful that if I don't train her right, she will end up thinking she's allowed to be territorial and aggressive. Since I've always had started with puppies, it's much different to train an adult. I don't know how much socialization she's had or if she will develop more aggressive behaviors as her personality shows itself more. If anyone has advice, guidance, or reassurance that I'm heading in the right direction, I'm all ears.

It is early days. Treat her as though she is still a very young pup. Go back to basics and do what you did when you had other pups. Don't take her to over populated places. Take it slowly.

It seems to me you are doing all the right things. Rescue dogs can take a while to settle and it's only been a week. Be patient and keep doing what you are doing.