Having read through the thread, I think you were starting to get into the right mindset for how GW1 actually plays. I just wanted to add a few thoughts on top of the advice others have already given.
GW1 is fundamentally a game about team composition and tactics, you are the main character of the game however, if you treat your team like that you wont go far. Prophecies starts out very slowly, and it's really Nightfall and Eye of the North that begin to open the door to experimenting with different party setups, as that's when you gain access to your first heroes. Unfortunately, Prophecies was released at a time when the expectation was that players would group with other people rather than rely on henchmen.
You absolutely can beat everything in this game with non-meta builds and without consumables, provided your team composition works and you play around its strengths. On the other hand, you can also run individually strong builds with poor team synergy and still fail to clear Normal Mode.
The wiki is an excellent resource for looking through skills and understanding what they do. As you play, you'll also start to get a feel for how the AI behaves. A rudimentary example that you have probably encountered is scattering of mobs when firestorm is cast on them, which means other AoE skills are less effective. You counter that with snare, so something like deep freeze would help get the most out of fire storm. Containmentbreach's Fevered Dreams composition is a great example of this kind of synergy done well in a much more indepth way. Complement this with weapons, weapon mods, insignias and runes you get some incredible depth to gameplay. I could run all the same heroes, but have different weapons/mods/insignias/runes and get a completely different result (for better or worse).
As for primary and secondary professions, your primary profession determines your primary attribute (in your case, Strength, which no other profession has access to), your maximum armour values, and your energy regeneration. Warrior/Elementalist does have some synergies, such as Conjure Flame and various touch skills, as mentioned earlier in the thread, but is lacking in the energy department, so if you wanted to use these kinds of things you would need to start looking at how to not be sat doing nothing whilst you wait for energy to regen (zealous mods, adrenaline skills, signets etc). The Elementalist skills you'd likely want are fairly limited in early Prophecies. It's also worth remembering that just because Elementalist is your secondary profession doesn't mean you need to use Elementalist skills on your skill bar right now. There are plenty of Warrior-only bars that work perfectly well, and later in the game you'll be able to change your secondary profession whenever you like.
GW1 isn't a game that rushes you to the endgame it's a slow burn. Stick with it, spend some time theorycrafting your team composition, and you'll be well on your way.
