midrand: Is this how it's meant to be in the D&D Universe?
_Pax_: Yes.
Charisma is literally your Personality attribute; all social skills are dependent on Charisma.
Not true, sometimes you have an option to make a check using a different attribute, eg. Nature or Religion, which uses the corresponding attribute. It doesn't happen often, but I've seen it pop up several times already.
Howevver in most cases you usually get Persuasion, Deception and Intimidate, which use CHA, so I recommend picking a background or skills that add proficiency in them (or just one, depending on which options you will be using).
Also Friends is supposed to give you an advantage on Charisma checks, so if you cast it before talking with someone, you should roll twice and use the better of the two rolls - I'm not sure if it works ingame or not. Someone said that supposedly it doesn't work yet, so check whether you actually roll with advantage or not when rolling it.
I'm playing as a Wizard and selected Persusasion as a proficiency, and with +1 Charisma, I'm getting +3 to all rolls using that (which helps considerably), and casting Friends when I can. Ultimately, even if you pick a CHAR class, it only gives you +2/+3 more (if you reach 17/18 CHAR), so personally I think it's not worth it to pick a CHAR class for the dialogue options unless you really want to, esp, if you have fast loading.
Edit: Just to be clear, it's not such a big deal - if you put +1 in CHAR plus pick the relevant skills you want to be using, you should be good to go and you will be able to persuade others, otherwise it's justa matter of reloading and rolling again. And if the Friends cantrip works, you have an even bigger chance of succeeding, as you roll twice and use the better number automatically.
In 5e you need to roll higher than a number you're given - eg. 10 or 15 on a D20 and the threshold for the difficulty check is 20, so you are always able to succeed at a check with luck/RNG. And in this game your bonus gets detracted from the total. So instead of needing 15, if you have +1 to CHAR and proficiency in Persuasion, you get a +2 for being proficient in a skill, so you have a total bonus of +3, therefore you only need to roll 12 or high. If you are rolling with another check, like Nature/Religion, then you would use the attribute and the +2 if you have prof even when it's a check done in a dialogue. So if you're playing as a Wizard, and need to do a History check, for example, you get +3+2, so you need to roll 10 instead of 15, while it would be 12 if it was a Persuasion check.