First time visit from Scotland/UK

Hi all! I wonder if you can help. I’m visiting Bolivia for the first time in April, solo and staying in Santa Cruz (but im visiting family). I’m a UK born citizen, however I want to get my Bolivian birth certificate and passport (my father is Bolivian), when I’m over as we are considering moving from Scotland. has anyone been through something similar?

additionally, any recommendations for phone providers? am I better getting coverage before I visit or better to get a prepaid sim when i’m in Santa Cruz? I’m also looking to fly to La Paz and Oruro, am I better pre booking here before I arrive or is this easy to do in Santa Cruz?

any information / advice is so appreciated 🙏🏼