Answer:
Having a GED does not indicate a reduced potential for a college degree. All that a college may require is additional testing for admissions and placement. Once you get into your undergraduate program the GED becomes irrelevant. However, most graduate programs require a certain test. It is important to prepare for, and take very seriously, any graduate test that may be necessary as these scores are (generally) heavily weighted.
In a nutshell, the degrees you will need are: Bachelors, Masters, Ph.D.
Some fields of study allow you to bypass the masters. Find your area of interest, then research the school's requirements.
You must take the ACT and/or SAT to get into college and the MAT and/or GRE to get into graduate school. Check with the college of your choice to learn which tests and the minimum scores they accept. Even if you are admitted on a probationary status, they might retain you in their program if you perform well academically.