fielding question

will a player rated 2e20 make more errors than a player at the same position who is rated 2e10 and if so why would they both be rated a 2....whats the difference?

The 2 is the "range factor" which is basically how many balls he actually will get to. The e rating is the number of errors that player is expected to make in a full season.

what does that mean as far as which player will give up more hits...when looking for a defensive player what do you look for and why?

First, the result is not perfect, but this is close. You always have to make assumptions to get results like you seek.
https://www.baseballthinkfactory.org/btf/pages/basesim/stratfldg.htm#3B
Note: the best way to view these is as benchmark comparisons, not absolutely deterministic results. Again, because it depends on assumptions--but the assumptions are the same for all calculations, so at least you have a measure of relative thresholds, like is a 4e18 better than a 3e35 at 3B. But not that a 3e35 will result in x hits per season, or that it would be 5 hits better than a 4e18.

It is based on the fielding charts (Super advanced)
https://somonline.fandom.com/wiki/Charts

what does that mean as far as which player will give up more hits...when looking for a defensive player what do you look for and why?

As for the rest of your question, everything is relative.
When looking for a defensive player, I don't. I look for players that fall within value thresholds.

That is, it is difficult to isolate defense when considering player price. Because it depends on your team, park, the player price, and their offensive contribution.

Guiding principles:
Range (the first number) is much more important in the middle positions (SS, 2B, CF and to a degree, C and P).
Errors are generally more important than range at the corner positions 1B and 3B. Also LF and RF, but poor range can be costly at any OF position. Check the fielding charts wiki from SOM in the link previously, since clearly you don't have the board game or CD ROM game and it is difficult to understand otherwise. You may have to read the base rules to understand them.

But I would still urge you to view players as a complete package, not as defense or offense, unless they are strictly bench role players.
What does that mean? Well it may not be feasible at 80M to have a team of all 1 range--you won't have enough for offense because those players have a high premium on price.