Access to any GenAI API for students for free

Hi, I am very much interested in exploring Generative AI and I would like to burnish my credentials by working on a lot of useful projects that incorporate genai. However I am not sure on how to start. By this I mean I am not sure how to access any genai api (openai/gemini/claude etc etc…) since I believe everything requires a paid subscription. I am particularly interested in exploring langchain and its integrations with openai/gemini etc. Langchain documentation is not of much help to be honest. So if someone could please tell me a way to access openai/gemini/claude apis for free and integrate it with langchain, it would be great. Again I am only a student. So helps if I can get some lead. The lack of access to apis is my main issue.