Guatemala is all about climbing Pacaya volcano, wandering the cobblestone streets of Antigua, and watching the sunrise over Lake Atitlan. You want to aim for the dry season between November and April, when the skies are clear and the trails are actually walkable instead of caked in mud.
A typical trip runs about $1800 all-in for flights, food, and lodging. If you want to spread that cost out over time rather than dropping it all at once, you can use the Discover it® Cash Back card and its 0% intro APR for 15 months on purchases and balance transfers to pay for it in chunks.
That intro window is a hard deadline, not free money, and any balance left on the card when those 15 months are up will start getting hit with regular interest charges.