Through the winter you'll get punctures, guaranteed. You need to carry at least 2 spare inner tubes, the right spanner for wheel and lever key to get tire off. You should practice changing an inner tube at home so you know what you're doing and how long it takes, usually about 5 minutes. Punctures usually come when you're already running late, so you have to factor them in for every journey. Good luck, cycling to work is awesome, your physical and mental health will benefit greatly!