I’d say the first thing you need to do is decide what your goals are, because that will affect how you set up your training or what program you do. Are you looking to lose some weight? Do you care about strength in specific lifts, such as squat, bench, deadlift, etc? Are you looking to eventually compete in bodybuilding? You mentioned that you want to get back into “bodybuilding style training,” but this also has a ton of different options.
The next thing is to find a program that you want to do, not necessarily what you “should” do. When getting back into the gym, especially after a long lay off due to burning out, enjoying it is important. If you then decide you want to focus on one style of training, whether to compete or not, then you can look at what specific program will get you to your goals.
I’ve been training for 23+ years and have done a ton of different programs in that time, from solely body weight, to a body part split, push pull, several powerlifting templates, running/swimming, etc. Am I as good in any area as I could have been if I focused on one style and one program, no way, but for me, my goals changed throughout the years and so did my training. Because I always trained how I wanted and changed when I wanted, I can now honestly say I have loved training, still do, and have no intention in stopping. That is what is important to me.