you need to find your tribe - there are different cohorts of dog walkers where I live, they inhabit different walks and walk at different times.
For years I did one walk before work with my dogs, 8am by the field. We knew all the dogs and they all knew each other, it was lovely.
Now I'm retired I have more choice about where I go. I find the walks that are more countryside, forest, fields etc. tend not to have on lead dogs. These dogs might be fabulously well trained or a nightmare. One local walk has had loads of problems recently with attacks by out of control dogs, because it's a wooded area the guilty owners have been able to disappear from view quickly. I'm not walking there ATM.
The local park is nicely contained and has its regulars. The dawn patrol, walking before work, purposeful, not wanting to linger and the dogs tend not to be playful. The 8.30 - 10am slot is mainly taken with friendly off-lead dogs, often family dogs who are being walked after the school drop off. Owners have all "been there, had the embarrassing puppy" and are very tolerant of grumbles and the odd humping. The dogs have their mates and get very excited when they spot a familiar tail wagging.
After 10am you get more dogs who don't want to mingle - some on lead, some not, but the owners choose to come out at a time to avoid the play group.
Another popular walk is along an unused rail track, where you get a lot of elderly walkers with and without dogs. Vigilance is the key here if you have a dog who loves strangers (one of mine makes a beeline for older women who remind him of his original owner - I have to get his attention if I spot one of those).
I think you'll gain more confidence in handling his interactions if you can find a friendly group in a place you go to regularly - you'll see him interact and other dogs respond, you'll get a lot better at understanding dog language and which dogs are approachable.
This morning I put little dog on the lead when I saw him eyeballing an elderly white fluff ball (about his size) who was going to the loo, a dog I didn't know. As soon as he'd finished he turned towards us and his whole little body went into perky play mode, he did a little bow in our direction so I let little dog off the lead and they had a lovely minute of bounce and bow and bottom sniffing, then were both happy to continue on with their own owners.
You do have to be eternally vigilant and watch for signals, triggers, dogs on lead etc etc. Owners who walk along glued to their phones, not paying attention, are a menace.
My biggest bit of advice is to have training treats with you that are irresistible - his absolute favourite thing - ONLY use that treat for recall when out and about, not when you are home. IT has to be the bestest thing ever, nothing should be better than it. Roast chicken works well - when you have rock solid recall (which takes time) you will gain in confidence.
One of my dogs can be off lead most of the time as she WILL come away from other dogs and not approach them if I call her, one is reactive and always on lead, one is a work in progress but getting there.