The standard RX antenna set uses MCX connectors, they are small, lightweight, and give a clear click feeling when pressed correctly in, it is normally recommended to fasten or secure the antenna wires, so no direct force or vibrations go into the connector. Just leave a little free loose bend of the wire, so when plane parts move, the connector stays in.
The RX antenna consist of TWO wires, they both act as part of the antenna, so be sure none of them are all straight and parallel with the coax cable, about 5-10cm distance in the end is fine. When you mount the antennas in your plane, dont tape them directly on carbon or near wires or metal rods, this can be hard on some planes, but try your best.
Try to make BOTH the RX antennas most visible from the ground, how this is done best, depends ALOT on how you want to fly.. UP for hight altitude projects ? or just far away while not the hight ?