What job opportunities are best for an Infantryman/11B/grunt after being discharged?

I would focus less on your Infantry skills and focus more on your Army skills. Your Army skills are vast and most civilians don't have the same skills or it takes them 20 years to develop. Leadership, integrity, mission completion, task orientated, quick learner. If you think about your time in the Army you were thrown into many different situations and each time you were successful - that means a lot to a civilian employer but you have to get all of the military jargon out of it.

A lot of Soldiers say I deployed 4 times when they should say on 4 separate occasions I was sent to a unknown location to set up operations. I took a team of __ personnel and within __ days we transformed the setup location from nothing to fully operational. Once operational we started to build an infrastructure that would support bigger team and a larger support team.

You have the skill sets to be better than the majority of workers in the field already - you just have to go and let everyone know it.

When you served your 4 years or retired, don't stop! Go to school is very important in today's job market. School for anything, just do it. Your first year of school is basically going to see how much of your HS stuff you remember any how. Go from there. Don't stop!
What I did was went 4 years in Math and Physics. Then was recruited back into the Government doing work that my army days more than prepared me for at a substantial higher salary. All I can say is I had a fun time.
Just never stop learning. And btw, not all people are cut out for college. If trade school is the way you want to go, God Bless you and do a great job!

Don't limit yourself go back to school get a Trade if you are good with your Hands. or Law Enforcement but get a Criminal Justice Degree to put you in the door. or Postal Services, Park Ranger if you can give classes to Soldier and march 12 miles and like the outdoors you can be one. I took two trades A CDL Truck Driver and Industrial Refrigeration and I make more money then my Brother who has a Masters Degree in Human Resources .

Security guard comes to mind.

From my experience, the civilian world really doesn't care what your MOS was, unless it was a specific skill that you are trying to use after the military. If you were an electrician in the Navy, then you will have a leg-up on an Electrician job. If you were an Infantryman, you will most likely be recognized for your general service.
I was 11B, and since I ETS'd, I have been working in municipal water and sewer for 20 years. My old 11B friends now work at power plants, prison guards, IT geniuses, cops, Electricians, an NYC Metro bus driver, and construction workers. None of them have jobs with any 11B-needed training.
Did any of those guys mold their skill set in the Infantry? Yes and no. It molds the man.

Entrepreneurial ship: Every major characteristic necessary to be a successful entrepreneur is already embedded in the typical successful infantry unit leader (E-6 and above). We may not have all the skills necessary, but skills can be learned, what we already possess are the characteristic of the successful entrepreneur.

However, because of the steady and secure pay check we become used to in the military; this mindset gets in the way of taking the chance at going into business for yourself (its not that difficult). I learned in 1988 as a Drill Instructor, how to start my own leadership training company teaching the Marine Corps leadership traits and principles; (go figure) it was the only thing I knew that I thought I could charge money for, and people paid me to learn it. Then I develop a network of others that taught others how to start their own part-time business (many AD Marines and Sailors in southern CA). This grew into a success coaching practice and now a company that trains people nationwide to become successful health and wellness coaches.

The following 9 characteristics of successful entrepreneurs was taken off Monster.com. Notice 8 of the 9 describe the typical infantry squad leader, only #4 needs to be learned. What do you think?
1. Motivation
2. Creativity and Persuasiveness
3. Versatility
4. Superb Business Skills
5. Risk Tolerance
6. Drive
7. Vision
8. Flexibility and Open-Mindedness
9. Decisiveness
Any infantry squad leader can start a successful entrepreneurial venter if the approach it like a Plt Sgt getting ready to deploy back to a combat zone.
Ref: https://www.monster.com/career-advice/article/entrepreneur-traits

During my break in service I had some success in the security field. I started off as a regular officer and in just a few months I was made a dispatcher. Then a few months later I was made a sergeant and my job was to inspect other guards. Eventually I was made a an inspecter of sergeants and was being offered more money and responsibility. I left the job to relocate to another state. But in only a year and a half I progressed very quickly because of what I had learned and experienced in the infantry.

From what I know of 11 Bravos, they can definitely do it all. These guys have the "get it done" attitude to be successful anywhere. It's impressive to check out the RP 11B page and see what all these warriors are doing today.

I would say that the opportunities for an ex-infantryman are only limited by the interests of the ex-infantryman. Some fields that immediately come to mind are police officer, security specialist, and firefigther. Some not so immediately apparent would be diplomatic security agent, Immigration and Customs, Border Patrol, US Bureau of Prisons, Treasury or IRS agent. I have known ex-infantrymen who have went on to become lawyers and members of the diplomatic service. The only limits are those you put on yourself.

Going to college was a great transition after infantry life