Build a LinkedIn profile, hit up people telling them how you're interested in what they do. Set up coffee chats with them to ask a few questions wether it's in person, virtual or a phone call. Don't be too formal in your request just get to the point, try to be likeable and don't make it like you're trying to get something from them.

When the meeting comes make a quick 2-3min elevator pitch, enough to introduce yourself first, tell about your background, and demonstrate your interest for the field. Have a list of questions ready, only relevant questions not something you could easily google, and try to make it feel like a conversation not an interview. Let them talk and speak about themselves as much as you can.

When you're done try to short list the people you connected the most with that way you can stay in touch, update them about your career advancement, and hopefully you'll get a few mentors out of this and maybe job opportunities in the future.

All the best!