How do Skill Proficiencies work?

[Echo]

In the character creation screen if you go to Abilities > Skill Proficiencies you can choose to put +2 to two different skills. I was wondering if you take ALL of these skills with you or just the skills you put +2 into. Also would it be better for me to put +2 into a skill that has 3 points or 0 points in it?

[zero]

you get them as they are shown.

in general: getting them to +5's is better, you have 3 other team mates who can cover for what you are bad at.

[Snaef]

If you pick a skill, you get to add your proficiency modifier (and stat modifier) to skill checks.
This bonus starts at +2 and increase as you gain levels.
If you dont pick a skill, you simply use your stat modifier for skill check.
Different skills use different stats as a base.
Knowledge skills are intelligence based, stealth is dexterity based etc.

[FoxFox]

Not exactly clear on how this works, but your basic options are to specialize or to be a generalist.

In general you have +X on d20 rolls with X determined by your ability score (e.g. 12 = +1, 14 = +2, etc.).

Each skill is based on an ability. So if you have Charisma 12 = +1, then you get +1 on Persuasion rolls, because Persuasion is based on Charisma. Having proficiency in Persuasion gives you an additional +2 on Persuasion rolls.

So you can use Proficiencies to compensate for low ability scores, or to specialize in certain skills. Both can be viable depending on how you want to play.

[Snaef]

Also note, that some classes get 2 skills, some get 3 or 4.
Expertise lets you double your proficiency bonus (rogues and bards get this)
And some races get fixed racial skills or pick any one (human)

[RealDealBreaker]

Skills work like in real life. Everyone can try to subtly take a note off the corner of a desk with people around (covered by slight of hand) but some people are much better at than others.

So strictly in game terms, every character has every skill. Every skill +/- is determined by the ability score modifier of the related ability score (e.g., dex for stealth, wisdom for perception, etc.) and if a character is proficient in that skill then they also add their proficiency bonus (starts at +2 and increases to +4 at by character level 9, in tabletop it caps at +6 which is obtained at level 17). So a character's skills will range from -1 (the character has an 8 or a 9 in the relevant ability score giving a -1 modifier and they are not proficient) to +11 for most skills/characters in tabletop (though class some class features, namely expertise and the barbarian level 20 feature, will allow even higher modifiers for skills).