It's illegal to raise the output power above 4 watts. And even a doubling of transmit power is barely (!) perceptible at the other end. And technically speaking, that's literally the truth. A 3 dB (decibel) change is about the minimum change in level the human ear can detect and it takes a doubling of power to produce a 3 dB change in power. And if you barely reached the other person with an illegal amount of extra power, how will he be able to get back to you if the guy at the other end is only running the legal amount? I've kept my CB at the legal 4 watts since the late sixties when I built (yes, built) my first CB because I understand the reason for that power limit. CB channels are very narrow and spaced closely together. The more power the CB transmits with, the wider its signal and the more apt it will bleed over into adjacent channels. I've had some YAHOOs running way too much power that would wipe out 4-6 channels. I guess I can use the word 'assholes' here for those yahoos. For that reason I'm a strong believer in staying with legal power for CBs. The sky's the limit for ham radios which don't rely on narrow channels like CBs do. My ham radio in my Jeep puts out 75 watts, my ham radio at home puts out 200 watts. So I'm not against more power, I'm just against more power when it's harmful to others trying to legally communicate... like on the CB band.
And yes, CBs are still the way to go for offroading. 99.9999% of offroad events use CBs, only a very small number of people use ham radios but most of them also have CBs so they can stay in touch with those who only have CBs. I have both ham and CB radios in my Jeep and the CB gets used 100 times for every time I use the ham radio. It's rare that I even turn the ham radio on. So yes, definitely go with a CB first. Once you get that working and the antenna tuned, you'll be good to go for joining in on the various 4x4 group runs.