Larian Studios Forums Baldur's Gate III Baldur's Gate III - Build Discussion Help with my first character

First, yes you'll be able to get Haste with this setup. For stats you'll be able to respec as your gear pool widens so it's not too much of a worry. In creation I'd say start Fighter just to have a second set of medium armor in the party with no effort and set your Additional bonuses to +2 STR and +1 INT and then total I personally would run:
16 STR
10 DEX
12 CON
16 INT
10 WIS
11 CHA

But that's because I hate negative modifiers, so you can dig points out of DEX and WIS if you want (though save WIS for last to dig points out of it since Insight is a nice dialogue skill sometimes). With this spread at Fighter Level 4 or 6 you can pick up Actor for the +1 CHA and Deception/Performance benefits and/or Skilled. Fighter 8 is where I'd pick up War Caster since Level 3 spells will be opening up right after that with Fighter 9/Wizard 2. Soldier background probably helps out your approach more than Outlander so that you have the Intimidation proficiency without having to think about it, otherwise even though you didn't list it as one you want for flavor, Guild Artisan's skills are top tier for dialogue and you can check your skill proficiencies to make sure Intimidation is chosen manually in creation which then severely reduces the appeal of Skilled to bump your dialogue abilities and frees up Fighter 6 for a different feat or attribute bump if you want that.

I too recommend either starting Fighter and taking it all the way to 5 before the first Wizard level, or Wizard 1 and straight for Fighter 5 after that if you want spell utility early. Fighter 6/Wizard 2 depends on if you want your next feat/attribute bonus or your casting school benefits first and then free sailing from there.