Karala, he's really beautiful!
Mine would lunge and bark at other dogs. It was really difficult as she's heavy and strong. She's not aggressive, it's more fear combined with overexcitement
I tried a training class but she couldn't cope with being face to face close to other dogs and it became too stressful for both of us.
Because she loves food above all else I carried food with me ( and still do ) and gave her something whenever we saw another dog, before she got close enough to react. The lunging soon stopped, and whenever she saw a dog she would look to me for a treat.
I avoid the green areas where there are dogs off the lead and always cross over if we see another dog approaching on the pavement. Lockdown made me look less odd!
I've had travellers' dogs before and they were fine with other dogs except occasionally if a strange dog rushed up to them when they were on the lead. I'd be very hopeful that yours soon will be too.
My present girl was apparently always a pet but not socialised with other dogs and not exercised enough.
She also sometimes does the stopping and standing still and looking anxious. I give her a moment and coax her on. She won't move if I stand ahead of her, it has to be beside her, if you see what I mean.
Calmness, perseverance and routine have brought good progress. Our walks are still a bit lacking in variety (luckily I live in a nice area) but I just accept the limitations, she's such a sweetheart!