Adding to M Chin's answer, if you're interested in undergraduate research, you can email professors in the psychology department of your college whose research you find interesting! Lots of professors are looking for research assistants and those who are interested in your background will schedule a time to speak with you. In your email, you should include why you're interested in that professor's research, any background qualifications, your resume, and a request to meet to chat about their research.
If you're looking for summer research opportunities, here is a link from the APA regarding Undergraduate Research Opportunities and Internships: https://www.apa.org/education/undergrad/research-opportunities. Although some of the links may be out of date, try googling the name of the program to find this year's application!