Welcome "Grandpa"...here's my suggestion..I'm assuming you don't have any injuries or anything...if you are'nt familiar with these lifts, then learn them. Never sacrafice your form just to lift heavier weight...or you will def injure yourself. Learn the correct form/technique on each and every movement !!!!!! Keep weight very light until you're comfortable moving up slowly!!!
Workouts - build your workouts around 4 basic compound movements...incline barbell bench presses, barbell deadlifts(off the floor), standing front barbell military presses, and barbell squats.......perform these exercises on consecutive/seperate days.................add secondary/trimmings exercises to each workout
Diet - don't go more than 2 hours without eating..every meal should contain a lean protein choice( eggs, fish, lean red meat, protein shakes, chicken breasts, etc) ......include complex carbs(oatmeal, rice, whole wheat products, sweet pot, baked pot, etc) with half of these meals..especially meal #1 of the day and directly after your daily workout.
Stay away from sugars and saturated fats.....try this for a consistent 3 months
pretty basic stuff I've suggested...key is to be consistent in diet and training..perhaps some others here can add input as well...