From my experience of training five dogs (mainly rescues; wide variety of ages)...
Always crate train, whatever others upthread have said. This gives the dog their own safe space, and means that you can shut them in when you have visitors they mustn't mix with, or tradesmen who seem unable to shut doors behind them. It also helps with toilet training as dogs don't like to soil their beds. And, if ever you need someone else to look after them in an emergency, it's way easier for everyone.
Make 'stop/wait!' and recall the most important things that you train: they can save lives.
From my experience of having my first dog run over and killed, and having just seen exactly the same thing happen to someone else's dog on the walk from which I've just returned.....
Do not let your dog off the lead, ever, unless you are in a completely safe, enclosed space. Just don't. They are animals. My first dog was a velcro dog, a border collie, who was trained to respond to the flicker of an eyebrow, but he still lost control one day and chased a fox across a main road. It was the worst day of my life (and I've had some awful experiences!). Don't let that happen to you..... please.