Hi Veena,
Welcome to Wikitree! There are a lot of friendly, helpful, knowledgeable people here that are happy to collaborate with you. I see you are only a guest member and have not become a full member. You will need to upgrade to Wiki Genealogist Level and sign our Honor Code to receive your wiki genealogist badge, which is a necessity for editing profiles.
You should start by adding your parents and what you know about them (dates and location of birth/marriage) with a source. For the most recent generations, the only source you have may be personal knowledge. Next add your grandparents doing the same thing. Usually by grandparents, you will be able to locate them on a census (if they lived in the U.S.) and perhaps a marriage record. Keep going until you connect into the Wikitree (meaning when you go to add someone, you discover there is already a profile for them).
If you run into a brick wall (meaning you don't know the parents of someone), feel free to post here on G2G and list what you do know about the person. Be sure to include the link to their profile.
With your Scottish connections, you may at some point want to join the Scotland Project. They have a terrific group of leaders and coordinators.
I wish you all the best in the search for your roots!