So what's your current diet look like
Try be as accurate as possible yeah
I'm talking exact meals of breakfast lunch dinner and anything in between and if you know the serving sizes then even better
Congrats on beating the Tumor, use that motivation to make your life healthier than what it is now.
As plenty have mentioned, diet is going to be your best friend or your biggest challenge but the positive changes you can implement to it will reap the biggest rewards for you.
Your goals are very conflicting, you should pick one, and then within that goal pick a specific goal within that category.
For example if you want to lose fat, you should aim to lose 20 pounds by January next year.
Then within that goal, set another goal that is more achievable, and then after setting that goal, set another one that will be even easier.
I find by setting many progressive smaller goals that lead up too the big one, you stay more motivated.
I mentioned forgetting whatever you thought was good before and forgetting it because as a noobie, you probably see a huge bro at the gym or your favourite body builder do it, so it must work for you.
Unfortunately genetics and health reasons are reality, and believe me in your case they are obviously working against you, so you gotta be smart about how you go about it.
Pick a simple but constantly evolving workout plan that doesn't major in the minors.
Do compounds, (bench, squat, shoulder press and deads) and if you can't do them, do assistance work to build up to them (bench = push-ups / squat/dreads = squat no weight or weighted lunges / no weight shoulder press and start on your core.
There are plenty all over the T Nation website and have been linked here already.
And more importantly, do it and do it a lot
And sleep a lot
And eat lots of good foods
And do more of it
Eventually you'll beat that first goal and before you know it your well on your way to being a healthier you