How would you find out which lawyer to hire?

I have no idea what answer you’re expecting that would involve “my Grade-level reading ability”

Would someone with good reading skills be more or less susceptible to online misinformation?

Ability to detect misinformation online has nothing to do with the metric described in the headline.

Would someone with good reading skills be more or less able to read a simple (non-life changing) contract?

Most people just choose not to read contracts that don’t matter, whether they can or not. When was the last time you read a EULA?

They also tend to be fairly tightly constrained legally, since obviously society couldn’t function properly if the majority of people weren’t able to enter into the majority of contracts.