One thing I'd like to say is aren't most martial arts a hybrid of grappling/striking, etc.? Wasn't martial arts invented as a combative way to fighting in wars while also having the internal/breathing elements that sort of balance out the toughness? Correct me if I'm wrong.
Not really.
I'll follow up on Chris's post to point out that you've clearly tried to prepare by reading up on martial arts in general. Unfortunately, much of what is written on the subject is pseudo-historical myth and/or unreliable, overgeneralized marketing spin.
Let's break down a few aspects of what you've asked about ...
The overwhelming majority of existing martial arts (despite the etymology of the term) are not derived from military wartime usage. Most of them are civilian arts. Even most of those which have a military connection were never more than secondary aspects of training for soldiers.
Martial arts can range from 100% striking to 100% grappling or anywhere in-between. They can focus entirely on unarmed applications or entirely on weapons usage or some mixture of both. They can be highly specialized or more generalist. They can focus on combative application (in various contexts), sportive competition, long-term health, development of character, development of physical attributes, preservation of historical tradition, artistic performance, building a community, transmission of a culture, or any combination of those aspects. In addition, opinions may be sharply divided on the proper way to approach any of those options.
The "internal" vs "external" terminology is generally used in describing Chinese martial arts and the supposed dichotomy between the two goes back to some philosophical/political arguments in China around a century ago. Many of us from other systems see it as not much more than marketing.
"Traditional" is another word used so inconsistently as to be almost meaningless. (As witnessed by the fact that some arts commonly described as "traditional" (like Tae Kwon Do) are actually younger than some other arts commonly described as "non-traditional" (like BJJ).) It's commonly used as a marketing term to imply that students are receiving instruction in the same way that students have in previous generations going back centuries. This is almost always not really the case. (The closest you could get to that ideal would be the Japanese koryu arts, which are not that easily found and not what most people really want to experience.) What you typically get in schools which claim the "traditional" mantle are arts taught with various cultural trappings (language, ritual, etiquette, outfits, etc) from the countries that the art or its predecessors originated in. Sometimes these cultural trappings may be accurate to their origins and sometimes they have mutated significantly over the years and sometimes they are just based on uninformed fantasy.
"McDojo" is a derogatory term which is so poorly defined that it often means nothing more than "a commercial school that I don't think is very good." To the extent that it could be a meaningful term, I'd say it refers to a business model for a martial arts school which is focused on maximizing revenue through standardized practices such as belt promotion fees every few months, extra fees for special programs like "black belt clubs", fees for special classes on subjects which may be outside the instructor's actual expertise, and so on. You might actually get good instruction at a "McDojo", but it's a secondary priority to profit for the owner. Really though, there are plenty of schools which fit that description but still have students who are happy with what they are getting.
"Spirituality" is not something I would expect to be a significant part of the curriculum at most schools. Some places will give lip service to such a thing, but it won't amount to much more than a few minutes of meditation or memorization of an official creed. An instructor who spends much time promoting himself as some sort of enlightened spiritual guide is quite likely a wannabe cult leader. Depending on how you define "spiritual" it may be possible to gain benefits in that department, but those benefits come from the actual physical training and the mindset you bring to it.
All that said, I'll second the advice given by others. Forget your ideas about what you think a martial art is supposed to be. Decide what you personally want to get out of martial arts training (physical fitness, the ability to handle yourself in a fight, a fun hobby, whatever). Make a list of the schools in your area. Cross off all the schools which won't work for you in terms of cost, schedule, or location. Maybe post links to the website of any schools that you would like us to vet for any obvious red flags. Go to visit each of the remaining schools, watch a class, get a feel for the atmosphere and the teaching style. Many schools will offer a free sample lesson, try those out. Decide which school you might enjoy enough to actually show up and train consistently. (It doesn't matter if you find the best instructor in the world - if you don't enjoy the training you won't show up and you won't get good.) Sign up there and give it a try.