Hi there Aaliya,
Sociology looks at many, many aspects of society and how individuals and groups interact with one another are influenced by society (i.e. sociology focuses on external influences). Psychology is less about how society influences us and more about how we our influenced by things like our emotions (i.e. psychology focuses on internal influences). One example of how you could approach the same question from a sociological angle or a psychological angle is below.
Question: Why did so-and-so commit suicide?
Sociological approach: So-and-so felt disconnected from their family and community so let's look at their culture, their race / ethnicity, their neighborhood to understand whether these potential influences made so-and-so feel disconnected
Psychological approach: So-and-so felt disconnected from their family and community so let's look at their family history to see if there's evidence of depression that they might have inherited.
There's many careers one could pursue in both fields and they're often similar (marketing, social work). From a psych major, one can become a psychiatrist (focus on prescribing meds), psychologist (focus on therapy vs prescribing meds), psychiatric nurse (therapy and meds), researcher, among other careers. Sociology majors can also pursue research. Both majors are incredibly helpful for any career where you need to understand how people operate.
The first step to pursuing either of these majors, however, is to get good grades, pick out colleges to apply to, get your high school teachers to write you a reference for college and start writing applications.
First off, a sociologist studies sociology and therefore how humans interact and exhibit behaviors often referred to as "culture". A sociologist studies this to getting, usually, a bachelors degree in sociology.
A psychiatrist, on the other hand, is an MD. A psychiatrist studies undergrad and graduate studies in medicine, attends medical school, and eventually pursues their residency in a hospital. They are therefore full physicians, have a medical license, can prescribe medication and provide psychiatric counseling.
Sociology is the study of how a whole society of individuals (e.g a tribe. country or sect) think and behave as a whole. Basically the whole group is considered as one, strongly bounded to societal rules et cetera.
Psychology is the study of the individual human mind. It is more concerned with the minute details and oddities of human behaviour.
Psychiatry deals with the diagnosis and treatment of individual mental disorders.