What radio(s) you will need differ for what you are wanting to be ready for.
I personally have many radios in both the VHF/UHF and HF bands. This allows me to communicate with my family, friends and neighbors without needing any other systems, like cell phone.
VHF / UHF Radios
“Line-of-Site” radios are hand held, mobile or desktop radios, and great for keeping in touch with Family or Friends within a couple of miles. Hand held radios run on battery, but have a shorter distance capability.
“HF” or “High Frequency” transceivers , are used for communicating across great distances. They come in all different price ranges, and typically can be found used online and at yard sales or garage sales.