Anthony, first you need to decide what type of kart racing interests you. Sprint (classic go kart racing on small go kart road courses), dirt oval (generally small dirt ovals specifically designed for karts) or road racing (karts racing on sports car tracks, eg: Daytona, Summit Point, VIR, Mid Ohio, etc).
The best suggestion, if you’re not sure, is to visit each type of kart race and see what’s appealing. My guess is it might be sprints.
Find the track which you will/might race at and go see a few events. Ask a LOT of questions, see what classes are popular, what is your budget, how mechanical are you, the shops which support those events, what engine/chassis do they support, etc, etc.
Nearly anyone without racing or karting experience, I would recommend the Briggs LO206 classes. Extremely low maintenance, inexpensive buy in, no adjustments to the engines allowed. They are not fast, but they allow you to spend your time on driving and chassis tuning, as opposed to messing with an expensive engine package and high dollar rebuild costs. If wherever you decide to race, and if LO206 is popular there, I’d head in that direction. For what it’s worth, Margay Karts (check their website), offers a model called the Ignite, which come ready to race for under $4000 brand new. Used, good ones can be had for less then $2500.
No matter what you decide—–do NOT rush into it!! Take your time, learn as much as you can, talk to as many folks as you can, be honest on your budget and time. Unless you know EXACTLY what you want, stay off of eBay!
Have fun in your new sport. You and your Dad will have a hoot!!