The issue with loose leash walking is very normal and will take some time for your pup to master the heel position while among people and especially other dogs. Labs are friendly creatures which for us humans can be incredibly annoying. Though I was resistant for a long time I finally bought a tag so I can take Ajax to our dog park. The first 3-5 minutes he meets, greets, and sniffs like crazy -- no recall possibility at all during that period -- but then he settles down and I actually call him to the heel position and walk thru the area with the other dogs running around. We work on sit and down ( I never use the command "stay". The "sit" or "down" command is implied till he is given another command) while I walk away. It didn't happen right away but training in those often chaotic circumstances I have seen good results. Just a thought.
Where I live in order to use the dog parks, which are on county park land, one must purchase a permit. They give you a metal tag that you attach to the collar. The other benefit is in order to get the tag you must show dog registration and proof of rabies vaccination.
This has been very reassuring to read!I've just come in from a walk with Carrick who is nearly 6 months thinking where has all my training gone! ! In particular he has started jumping up at people in the park which given how big he is getting is really becoming a problem. Any suggestions other than asking them to turn away /ignore him?