I'm a newbie who is wondering about something I couldn't find any clear answer to on google.

I wish to play two character until I get the grip on the game and decide on which I wish to main.
The problem here is that leveling and doing quests is pretty slow on ESO.
Erh.. I mean... simply put, I tried to start both character in the same alliance but I feel like I overdose from the repetitive content which is a bad thing as it kills the desire to play for me at this point.

That being said, I was wondering how having characters in different alliances may affect my capability to play with other people from different faction.
Here I don't necessarely mean going through the 1-50 questing content, but more like the instancied dungeons, trials and the expensions as Orsinium (are these even faction limited?). You know, so that even though we aren't in the same alliance, that we can do something more than just speak in the guild chat.

Note that I am from Québec and as a native french speaker, I'd wish to join or create a french speaking guild and I fear to end in a situation where I have people -or myself- from X/Y alliance who have nobody to play with thus creating a feeling of ''left apart'' or worse 'feeling like being 'forced'' to create a new character so that they can play with the others, leaving what they consider their main for the sake of not playing the higher content, zones alone anymore.