El Salvador 4 day Itinerary Recommendations

I’m (25M) traveling to El Salvador traveling with a friend (25M) to El Salvador for 4 days in May 22-25, arriving early in the morning on May 22 and leaving in the afternoon on the 25th.

As know we want to do for sure is see the Santa Ana Volcano. We’re not big party people, and open to a good adventure.

We were thinking to start our trip for 1-2 days in Santa Anna (can we do the hike as soon as we arrive from the airport?), and 1-2 days in el tunco, then go to the airport straight from el tunco.

Are Ubers easily accessible or is there some other better form for transportation? What’s the best way for us to do this plan, and do you have any recommendations for where to stay, what to do, food, etc? Budget for the trip, not including flights is about $700 each maximum.