Occupational therapists (OTs) assist people (regardless of age) develop, recover, and improve the skills they want and need for daily living and working. They achieve this by using everyday activities (e.g., eating by oneself, driving, working). Examples of helping people include assisting children with disabilities in school, adults with injuries, and elders dealing with the changes of aging (both cognitive and physical). As far as where OTs work, the locations vary a lot including hospitals. clinics, rehabilitation centers, and schools.
Just to be clear, an OT is not a physical therapist. Although both may use similar techniques sometimes it is important to understand that an OT work with the environment to help people have an easier time with daily activities. Also, an OT receives specific training with those who have mental and emotional problems. Conversely, a physical therapist works with people to help them regain physical abilities (e.g., mobility, strength, balance and flexibility).
To be an OT you must go to graduate school. One thing to keep in mind if you want to go to OT graduate school is that you may need to take certain courses that Psychology majors do not always take (e.g., anatomy, physiology, chemistry). Currently you can be an OT with a Master's or Doctoral degree, although by 2025 you will only be able to earn a Doctoral degree. A Master's degree takes 2 years of study, whereas a Doctoral degree typically lasts 3-4 years. As is often the case, the more years of training you have, the more job opportunities are available. When you go to graduate school, it is generally expected that you will a full-time student. Tuition waivers, scholarships and stipends (a payment granted to a student) may be available.
Finally, to be an OT you must be licensed by the state you plan to practice in.
indeed.com lists the average yearly income for an Occupational Therapist at $86,000.