As Mister_X mentioned, in the US, start with the National Speleological Society at https://caves.org/ https://caves.org/ There is also a sub-reddit at reddit.c

As Mister_X mentioned, in the US, start with the National Speleological Society at https://caves.org/ https://caves.org/ There is also a sub-reddit at reddit.com/r/caving/ Definitely find a local group - if there are caves in your area, there are probably also cavers who explore them. Basic safety rules include: cave with groups of 3 to 6 people, some of whom have experience, bring 3 independent sources of light, use helmets and headlamps, avoid hand-held lights (a strong sign of inexperience or incompetence), leave word of your plans - where you are going, expected return time, who to call for help - with a trustworthy friend. Some basic knowledge of geology is useful, as is comfort with physical contortion, sturdy clothing, and an ability to orient and visualize in 3-dimensions in environments that are far from rectilinear. Respect the culture of secrecy about cave locations, which helps protect them from damage. Take nothing but pictures, leave nothing but footprints.