I want to switch to a release after shooting with my fingers For the past 20 years. I was messing around with a release and couldn't believe how much of a difference it makes. I am unsure how to set up my bow for this. I have heard I will have to set up my string differently, but I am not sure how. I also heard I would need to buy a new rest is this true? How big of an investment is this? Money is really tight for me.
Would it be possible to use my bow the way it is and just change my anchor point and re-sight in my bow? If I did would this damage my bow?

It really depends on what your current setup is...

When using fingers your arrow has mostly side to side movement.. and your arrow rest is normally designed to account for this movement. Normally this side to side movement allows the fletching to clear the arrow rest.

When using a release.. the arrow has mostly up and down movement.. and you need an arrow rest to account for this movement.. Also the arrow is normally being forced down into the rest.. and any fletching contact will result in very erratic arrow flight.

Depending on what kind of rest you are currently using.. would determine if you'd be better off sticking w/ fingers until you can afford a new rest also.

That makes sense. I should probably just wait till next season.