Congrats on your purchase!
I'm a big fan of the S&W M&P, I carry a 45 M&P 90% of the time and have done so for more than three years. I use to have a M&P 9mm C but my daughter liked it better than the G27 she had. Took awhile to find a buyer for the G27 and ended up selling it for much less than I paid for it all the same my daugher truly enjoys her M&P.
I expect you will discover this firearm will serve you well, practice often and enjoy your firearm. As for holsters, check out Don Hume, Galico and Highnoon. I like my Don hume but it's a ISWB, my daugher has a nice Galico and last year my kids got me a sweet highnoon custom soulder rig. Always found leather holster to fit/carry better that nylon or plastic holsters. That might be a personal choice.