Planned Guatemala Trip Guidance, Questions, Advice, Opinions!

Hi!! I will be traveling to Guatemala in a few weeks with three other females. We sort of have the typical itinerary, two days in Antigua, Acentango Volcano hike, three days in Lake Atitlan (San Pedro). I have done a lot of research but there are still things I am curious about and need some advice!

MONEY: I have read so many different things but I would like to hear personal experiences. Credit cards/bank cards, are they worth using at more popular spots? Should I bring US Currency and to exchange currency, I have read to not bother at the airport but find local ATMS??

LAKE ATITLAN: Again, so many blogs, opinions, thoughts on this area. Our airbnb is located in San Pedro sort of at the bottom of the village area. Most things I have read are relatively safe, just beware at night time. It's about a 30 minute walk to the heart of San Pedro, we are walkers whenever we can, is that area okay to walk to? And can someone explain the boat transport to me a little lol

LOCALS: I always try to support locals and local businesses when traveling, any recommendations that specifically benefit the locals versus the super tourist typical areas?

Nature Reserve San Marcos: We plan on going to Cerro Tzankujil for some cliff jumping, anyone have any personal experience with that or other areas that they would recommend going to?

Overall, we love the outdoors, exploring, learning new things, immersing into culture, and we have so very little time to do it all! I would love any recommendations, outdoor adventures, tours, locals to support, places best worth visiting!