Do respect other visitors & keep your dog in sight.
Some people are terrified of dogs and others may just prefer not to mix with your dog... however adorable they are!
Some dogs are also anxious about dogs they don't know, so before letting your dog approach other people or dogs (especially on-lead dogs) check that it's ok with them first. Groups of dogs approaching another dog may be particularly intimidating, no matter how sociable the dogs involved are.
Keep your dog in sight so you know what's happening and be ready and able to call them back to you if necessary. If they are out of sight you don't know if they have encountered wildlife or grazing animals and this could cause serious problems for them or for the wildlife.
It is also important for your dog's safety to keep them in sight, so they don't injure themselves (for example on barbed wire or snares) or eat something toxic (eg palm oil on beaches) and so that you can quickly respond to help them, prevent them chasing or getting lost.
Trainers recommend that when you are giving your dog off-lead exercise time you still call your dog back to you from time to time, giving them lots of praise and fuss or playtime with you and a toy or sometimes a food treat. This will reinforce their bond to you and their recall, so that when you do need them to come back to you quickly they will be happy to do so!