WRFX611

I am new to GMRS so I apologize in advance for my ignorance. I was working on connecting to a local repeater (12 miles away per Google maps) and had no luck with the rubber antenna on my handheld. I have since purchased a 3 element Yagi and a BTech GMRS-50 mobile radio that I have setup as a base station at my house. I can hit the repeater just find and communicate with the Yagi. I have recently purchased a J-Pole antenna (has yet to arrive) to try and improve my omni-directional range and to possible bring with me on camping/hiking trips, etc to setup a mobile setup. My question is (assuming the J-pole alone does not hit the repeater) would it be possible for me to connect both the omnidirectional J-Pole and the Yagi to my radio at home? If so, how would I go about doing this and what types of things do I need to be concerned with as far as placement of the antennas next to each other and such. Currently I have the Yagi mounted in my attic (HOA is not very friendly and I don't want to ruffle feathers). Thanks in advance for any help!