My advice for the novice, avoid watches with broken balances. You need specific experience and tools that both take time to acquire. It is truly a more advanced skill. Finding complete balances is an option or a donor movement, but generally speaking, avoid them. As has been mentioned getting into pocket watches first is a great start as everything is bigger, especially if you begin with size 18 movements. Avoid English Fusee movements as the majority of them were all hand made and all the parts were hand fit. Almost no parts are "drop-in" like the Americans pioneered. You will make mistakes, you will ruin parts or lose them, as we all have. You will curse and sweat and have nightmares, but when you succeed, you'll know the joy of watchmaking.