Why does it seem like starting position doesn’t put you in the best possible position for your Civ? Isn’t this supposed to work like starting bias in the previous games?
Would I be better off using balanced or legendary ( I think that’s what it’s called ) start?
I've restarted thousands of games so I might be able to help you with that. From experience, Civ 6 only places your Civ in its biased starts around half the time, and more than half those times the starts would be okay in the short term but terrible in the long term. I can't recall how many times I've started in the Jungle as Russia despite the game map settings set to cold.
Legendary Starts tend to restrict the placement of Districts and Wonders partly because you can't build them over Luxuries and partly because you'll be forced to sacrifice bonus resources you don't want to. Balanced does nothing to improve starts it just makes sure everybody starts on somewhat equal grounds. "Equal" here however is very flawed because it doesn't consider potential, district placement etc.
Therefore to offset the lack of long-term potential that the game tends to give players for their capital my advice is to Set World Age to new and Resources to Abundant. (Start Position as Standard) That way even if the base terrain they give you sucks it can be compensated with bonus resources and the presence of more hills also cushions your Civilization from being bottlenecked for lack of productive capacity. Freshwater is almost never a problem with starts so you can be sure that farms on those hills later is possible as well.
Of course, what you want for a start also depends on what you hope to achieve in the game.
If you're a warmonger seeking some challenge the start is quite irrelevant since you'll be getting what you need by robbing others.
If you seek a more peaceful route then a better start is compulsory for a more comparable advantage to warmongering because you'll have to build everything yourself rather than just take it off the AI.
Bad Start + Peaceful = Very boring game (Unless struggling is fun for you.) because you'll have to skip wonders/districts and focus entirely on settler/builder production so as not to lag behind.