combination feeding-getting started

Hi all! I am a FTM and on maternity leave for another 9 weeks. Right now I'm EBF but when I go back to work I plan on combination feeding with formula because I won't be able to pump at work like a need to and I think it will take some pressure off myself to produce enough milk. I'd like to keep doing his morning and night feedings, and pump once or twice during the day, any advice on how to get this process started? LO is only 3 weeks old so I have plenty of time I'm just not sure where to start! Thank you!!