Crossfit is really excellent for all around 'functional fitness' but in my opinion has too much injury risk, and doesn't focus enough on building strength and muscle, which are functionally useful, and are also key for looking fit.

I would recommend most people start with an introductory strength training program that does heavy compound lifts like Starting Strength, and having a professional coach spend a few hours at the start to make sure you're doing it safely. Heavy compound lifts have a lot of specific hormonal advantages, and can be used in addition to bodybuilding type (high rep/low weight) lifts.

This, coupled with a pretty standard high protein 'recomposition' diet will transform most peoples physique pretty rapidly. Look up the article "To Be A Beast" by Jordan Feigenbaum. Other more advanced 'powerbuilding' diet programs like LOOK STRONG NAKED, The Deep Water diet, the Vince Gironda diet, LeanGains, etc. require more effort but can get you both very lean and very strong.

orangetheory is just as good as crossfit