Keeping track of your lifts is the most important thing you can do to keep yourself on track during your workouts. Week by week, it is important to try to increase the amount of weight you lift to keep your strength and muscles growing. Consult your physician to see if weight training is safe for you.
Your diet is the most important part of achieving your fitness goals. Everyone's body is different and there is no one-size-fits-all diet that works for everyone. What does work, is recording your meals and tweaking your macros over time. Diet planning is tedious and time consuming, but hopefully, this journal will make it easier.