@potatobread This is a picture diagram that explains the other posters LAT and adds LAD (look and dismiss) use a clicker and high value treat to mark the look away
https://www.choosepositivedogtraini...-of-selfinterruption-the-engagedisengage-game
It is straightforward and distance is your friend
Keep the dog below threshold and in the zone where he can still learn (green/ yellow)
This is thresholds
https://www.diamondsintheruff.com/thresholds#:~:text=If%20your%20dog%20tips%20over,He%20can%20still%20think!
This is a really good video series with foundation skills and how to manage walks and use distance to keep your dog below threshold and avoid practicing the barking etc
One more thing... you may actually have a dog that loves other dogs (frustration reactivity is a thing and not all barking is fear) a trainer could assess and you do need to know your dogs emotions behind the reactivity to really help them
However you actually don't want to teach your dog to love all other dogs... certainly not when they are on the lead... your aim is to help them be able to be calm and neutral towards other dogs and just slightly interested
I would also say with a new dog lots of praise and bonding/ snuggling with their owner. Mark any calm behaviour. Play games like leave it, wait for food, wait for go find it etc etc and fetch... things that build up their impulse control
It is also good to consider enrichment with puzzle toys and kongs not just physical exercise. You can do scent hunts round the garden or house with food... take to green space and just do gentle meandering sniffing walks to help sooth and calm and tire the brain of the dog
https://aniedireland.com/100daysofenrichment/
Use what suits your dog and a lot is DIY and fun
Also make sure you have enough down time and naps for them and a a regular routine that makes calm times and reset a priority
Oh and a good idea to work through the calm protocol gradually once the dog has settled in
https://www.k9ofmine.com/wp-content/uploads/2021/01/Karen-Overall-Relaxation-Protocol.pdf
For all this go slow and take your cues from the dog... if they are a bit jumpy or tired and overwhelmed go slow and reassure and give a stress break! It is a big change for them
This is a slow steady journey for you getting used to them and being a skilled owner... trust is won!
I would see if I could get a very good positive trainer for even a few one on one sessions to set you up with the skills
