There are some things to consider before you start. Particularly now with genetics becoming a regularly used aid in genealogy, researchers are well advised to mention a bit about the possibilities to prospective clients:
This will be a very personal journey for you and while many people are delighted to learn their history, at times there can be unsettling revelations, both in distant generations and sometimes, those closer to us.
This could include revelations found in documentation: Perhaps you discover your ancestor fought on the “wrong” side of any given war. Perhaps you will be haunted by the discovery your ancestors wound up in a workhouse due to abject poverty. And sometimes dearly held family stories are discovered to be untrue.
For some, facts are facts and the truth is all that matters. For others, it can understandably be far more upsetting. It is certainly up to you how much you want to know as compared to what you may have assumed or been told. Your feelings on this can certainly be discussed.
Genetic testing as well can be a blessing or a curse. It may open up your world, provide answers to the unknown in a delightful way, or scientifically confirm exactly what you thought about your family members and your ethnicity. But it should be noted that it also can take a very unexpected turn. DNA testing is purely scientific and not sensitive in any way and so it has the potential to be even more unsettling than documentation. Between ethnicity estimates that can reveal you are from this place rather than that place you thought you were from, to the revelation of relationships you were unaware of, there is the possibility of discoveries you never expected. For all of us, it has the potential to be a treasure chest or a Pandora's box.
The point of genetic testing, aside from ethnicity estimates, is for comparison to others and finding (typically) cousins who may contact you or vice versa. For some people, they may find someone even closer they were unaware of or perhaps realize there is actually no genetic relation to someone they thought were. It can be a joyous discovery or an extremely upending piece of news. Clearly this is not always the case but it can and does happen.
It's also worth mentioning that professional genealogists are expected to follow a code of ethics. Your information will be confidential and if you wish to share my research with your family and friends, that will be your choice. My work is copyrighted so I would ask that you consider this in terms of how much you share, to whom and where, and that credit of my work is acknowledged.
Please do consider the unexpected journey that is possible in every family history and decide if it is truly right for you. When all is said and done, for most everyone, peering into the past is an enlightening, worthwhile and exciting journey as our personal history comes to light.