Read the FAQ, as you clearly don't know what you're doing. Nobody knows what they're doing when they first start, be one of the sensible people that actually read and learn, rather than spending months/years pretty much wasting your time.
Ignore your 'fitness instructor', he's an idiot.
Get on a proper strength program and follow it. There are several good ones out there to chose from, ICF and 5/3/1 BBB are good, read up on them and then you can make a decision.
You get stronger at squatting, benching and deadlifting by squatting, benching and deadlifting. You'll be able to comfortably lift the empty bar at the very least. There are several 'how to' videos on youtube to help you learn how to do the lifts. Nobody had perfect form to start with, it gets better with time, most important thing is that you actually do the lifts and try to constantly improve. The more you do them the more self aware you'll become and the easier it will be to fix form issues.
Don't do your strength training and cardio in the same session, if you "have to", do your strength training first and some cardio after, cardio first will simply waste energy and limit lifting performance.
You need to eat in a calorie surplus to gain muscle, as a result you'll gain a little fat too, if you can't accept that then you're never going to make real gains as you won't eat enough.
Naming foods is useless, what are the portions? How many calories? How much protein? etc etc etc.
Buy cheaper whey protein. MaxiMuscle is RIDICULOUSLY overpriced. They saw you coming a mile away.
Can you focus on upper body only until December? No. Follow a proper program!
How long will it take to notice considerable changes? With the plan you listed, you probably never will notice considerable changes. Follow an actual program, do it properly, progress and eat right and there will be noticeable change, although how long is a piece of string?