I opened utorrent to use it without root and the only thing I see is incoming tcp port. Will it automatically fill this in or do I need to put in another number?
No, utorrent won't work with Orbot if you do not use root.
incoming port option will not configure utorrent to use the Orbot proxy.
I just looked through the settings of utorrent and there appears to be no proxy settings, so unless you use the transparent proxy feature of Orbot (which requires root) utorrent's traffic can't be routed through tor.