Advice for starting a new job with an MSP

In a few weeks I'm going to be starting a new job with a local MSP as an outside network technician. I'll essentially be doing all on the onsite work for clients. This is a huge step for me as I've been an in-house jack-of-all-trades network admin/ IS manager for the past 17 years, 15 with the same company. Does anyone have any advice for transitioning into this role? What should I expect? Has anyone else been in this position? Any input would be greatly appreciated.