Your hotel is a block away from the office I work out of my Japan visits and not that much farther from my usual hotel.
Narita Express to Yokohama Station, then switching to a local train for 2 stops to Kannai Station was what I did for a long time. If you do this, take the north exit at Kannai as it has an elevator and puts you just a few feet from Kannai Odori street, the main street that one side of your hotel faces. (You could also do Narita Express to Yokohama Station then take a taxi to your hotel.)
For the last 2 or 3 years I've been taking the Airport Limo bus to YCAT, then a taxi to my hotel. I made the switch in part because I found the wait was shorter for the Airport Limo than for the Narita Express at my arrival time. There is also less lugging of luggage. There is traffic risk with the Airport Limo but I've been caught in a jam maybe 1 out of 10 times. Also, I tend to depart from Haneda so the Narita Express round trip deal isn't a factor for me.
Several 7-11 stores in the immediate area. Their Seven Bank ATMs are great for getting cash.
Feel free to let me know if you have Kannai-related questions.