D&D 5E Changing Character Mid-Campaign

[CleverNickName]

My favorite Core-Rules-only rogue build starts with a high-elf with the Criminal background. Put your highest stat in Dexterity and your second-highest in Intelligence, and prioritize Stealth, Investigation, and Arcana. Later on, consider the Arcane Trickster subclass, and maybe multiclass with Wizard to get better spells and access to magic items that can only be attuned by wizards (wands and staffs especially).

If your DM will let you use non-core materials, consider playing a Goblin. Nimble Escape and Fury of the Small are great abilities for rogues.

 

[Blue]

On that note, Im leaning towards playing a Rogue!
Which archetype and Race do you guys suggest?

I'd take a look at the Swashbuckler Rogue (published in both SCAG and XGtE). With their Rakish Audacity feature they get yet another time they can apply sneak attack which makes it very reliable, they have some social focus for your "25% social" request, and with their Fancy Footwork (which is a lot of the Mobile feat) they are great at getting in, going stabby, and getting out.

I'd recommend using two weapons with them - don't worry about the feat or the fighting style, the offhand weapon is just an extra chance to apply your sneak attack if you miss, another foe to apply your Fancy Footwork to, or if you don't need it use you bonus action for Cunning Action or something else.