Diet and nutrition are all over the place. What do you have access to? What does your body tolerate? What does it not tolerate? CrossFit does a really great job with their general dietary prescription in Glassman's World Class Fitness in 100 Words "Eat meat and vegetables, nuts and seeds, some fruit, little starch and no sugar. Keep intake to levels that will support exercise but not body fat." Before you lose your shit about CrossFit advocacy and MuH KiPPinG pULLups, this is a dietary guideline not an advocacy of the program (although I believe whole heartedly in CrossFit). John Welbourne's Talk to Me Johnnie blog has some really good nutrition articles as well. He has plenty of Paddles and Plaques from capable groups hanging on his wall to affirm his legitimacy in the tactical s & c world. For what you have said regarding "combining stimulating muscle and diet," think of diet as your foundation that you're building your house on. If your foundation is dog shit the house sinks and gets fucked up. Caloric deficit will make you smaller/leaner, caloric surplus will make you gain weight. Calculate your basal metabolic rate that is what your body burns doing nothing. If you have an accurate body fat % from a scan that helps immensely with accuracy. Theres your baseline for being in bedrest to maintain your current self. Now you need to add or subtract from that your activity level and desired outcome. Consistency in your tweaks and amount of time you maintain them will drive your adaptations.
Seeing your new post meow---
If you want to get strong enough to lift a Honda Accord etc, your journey starts with a barbell. To continue the Rip quotes (because Rip is the fucking man) "There is simply no other exercise, and certainly no machine, that produces the level of central nervous system activity, improved balance and coordination, skeletal loading and bone density enhancement, muscular stimulation and growth, connective tissue stress and strength, psychological demand and toughness, and overall systemic conditioning than the correctly performed full squat."
Train the big 3- squat, pull, bench. Probably hop on a Linear Progression. Add in some O-lifts which will replicate your throwing heavy thing across room. Do sprint work on ergs, on the road, and with sleds. Avoid over complicating it, by what you've said your training age appears young. There are some solid programs out there catered to just this, I go back to fan boi-ing Power Athlete, but Gym Jones used to have some solid strength/endurance templates as well (F giving them money now, since Mark left they are stagnant cancer). Your body has the ability to ride these adaptations for a bit unless you're missing a testicle or some shit. Mass moves mass homie, if you want to get stronger and apply force to objects and things your frame will start adapting to those imposed demands over time. Myofibrillar hypertrophy is king and results in more contractile potential which= more ability to lift shit. This growth weighs something, but its usable mass. Sarcoplasmic hypertrophy is primarily fluid volume generated by large sets of things, but a huge percentage of the gain is unusable to create contractive force.
Lastly, how to combine or how often? Some people advocate lifting and metcon on every training day. Some recommend lifting one day metcon next day. Some people train daily, some people go 3 on 1 off 2 on 1 off. It all "works," but it depends on what exactly you're doing. Everything costs something and we all must pay is something a mentor of mine often says. This cost of training comes in the form of degradation to your CNS and your musculoskeletal system. Every one must pay the man for that cost. Sleep is your biggest ally, diet falls in line closely behind sleep (gear is really number 1 or 2 here, but I digress), then you have all sorts of modalities to choose from that provide some what of an impact tertiarly to sleep and nutrition. SOO, how you mix them depends on what you're doing exactly and how YOU respond to the adaptations and how well YOU can recover from them given your daily tasks and routine outside of training.