Broad question, so here's an overview of the area:
Joshua Tree National Park (JTNP) is the tourist attraction. The entrances you need to know about are the West entrance (in the city of Joshua Tree) and the North entrance (in the city of 29 Palms). The best views, attractions, hiking, picnic areas, and campgrounds are near the West entrance. It is about a 45 minute drive from one entrance to the other (if I remember right).
Yucca Valley is adjacent to Joshua Tree (the city). Lots of stores (Starbucks, grocery stores, fast food). New sewer ordinance may add future cost to a purchase. There was some debate over the new STR ordinance, but overall not too restrictive. About 15-20 minute drive from Yucca Valley to the West entrance of the park, depending on where you are in Yucca Valley. City mostly populated by locals, which is why there was some neighbor complaints and debate about short-term rentals in the city.
Joshua Tree is a community and not technically a city (it is a census-designated place and considered part of the unincorporated zone of San Bernardino County, therefore subject to county laws regarding STRs). They are very community-oriented and do not want big businesses in their "city". They even successfully fought to not have a Dollar General Store open up in the community. Therefore, Airbnb's (and STRs) are a large part of the community economy since there are no large hotels or motels. Airbnb is not likely to ever go away or be prohibited in Joshua Tree. Highway 62 runs through Joshua Tree. Generally, north of the highway, you can find cheaper real estate (esp if you are looking for wide open land and lots of multiple acres). You can also find the same as you head east on Hwy 62 toward 29 Palms (city where the marine base is located). As you head down Park Blvd (which turns into Quail Springs Rd) toward the West entrance of JTNP, you will find plenty of neighborhoods. Locals generally want to live south of the highway. A lot of great communities, but they get more and more expensive as you move closer to the entrance of the park (Friendly Hills, Upper Friendly Hills, Joshua Tree Highlands, Monument Manor). To get a big lot of land in these areas is likely going to be very pricey, especially as you move closer to the park entrance.
29 Palms is further east (marine base is located there, so you have the military-type community and strong traditional rental market). Wonder Valley is even further east (may be up and coming, but a lot of wasteland-looking properties out there still). 29 Palms is very STR-friendly and they recently passed an ordinance that favors STRs. However, the average daily rate as you head further east is lower than in Joshua Tree proper, even though you have the convenience of the North park entrance.
I own and operate 2 rentals out in Joshua Tree, one in Friendly Hills (less than 5 minutes from the saloon in a neighborhood) and one in Monument Manor (a mile from the West entrance and in open land, 7.5 acres). Most that come out to Joshua Tree want the open land and the feeling of isolation. However, our rental in the neighborhood still does well, as we did modern decor and market it toward all the millenials and city-folk who are heading out for short vacations.
I would recommend you look first in Joshua Tree proper, preferably south of the highway (although there are good rentals that do well north of the highway). Just know that although the tourism has increased, so has the # of Airbnb properties, so you have to be able to compete somehow if you want to keep your occupancy high. Find a way to stand out from the competition in a trendy way and you can do well.
Love the area and would invest in the area 1000 times over if I could do it again. Another thread here on BP said that if they were to invest in the area again, the one thing they would do differently is start 2 years earlier! Prices have increased dramatically, but there are always deals to be had.