There is a balance between spring tension and string tension. It varies with tuning and string gauge.
The trem bridge has an optimum float position. There are specifications to set it correctly:
http://www.prsguitars.com/csc/bridges.html
Lower tunings and lighter strings require less spring tension. Higher tunings and heavier strings require more spring tension.
Are you taking lessons? A good instructor can help you navigate the parts of your guitar, understand how things work and why. All of which can lead to better playing and enjoyment.
Getting your info piecemeal, one question at a time is going to hold you back. This a friendly forum and people are glad to help. But you may be hampered by not knowing what you don't know, thus not even knowing which questions to ask.
An instructor can cover lots of ground in just a very few introductory lessons...