You start the game near the Ranger Citadel, the headquarters of the Desert Rangers. Of course, this is not the only location in the game. At the end of each map, there is a characteristic globe icon, like the one in the screenshot. After you access it, you will leave the current location and exit into the wastes.
Out in the wastes, there are many other locations - destroyed cities, military facilities and regular encampments. At the very beginning, you do not know the locations of the individual areas so your map is completely blank. You fill it up by learning about new places, during the conversations with NPCs, or by traveling and discovering them yourself the remnants of human civilization. If you don't know where a certain location is, whether you discover it when walking close to it or not, depends on your Perception level.
When exploring the wastelands, you will need water. You can treat it like fuel for a car. You need a certain amount of fuel to get from A to B. When you run out of water, the team will start suffering from dehydration and receive damage. If you don't replenish water right away, everyone will die of thirst. The amount of water that you have is represented by the blue container in the bottom-right corner. Moving your mouse onto any location on the map will show you how much water you need to get there. There are two ways to replenish water. Firstly, from water sources in various locations, like for example in the canteen of the Citadel. You just have to click on the container and confirm that you want to get some water. Secondly, you will randomly encounter some oases when you travel. An oasis will appear on the map when you are close to it. Approach it and get water for your heroes. When exploring new areas, it is good to sometimes change your course to look for a place where you can find some water. The problem of water will disappear after you get to California, where there is no need to worry about your water supplies.
Moreover, you can also randomly encounter some secrets on the world map, in which you can find useful items, such as weapons and ammunition. There are also special shrines - locations made for people who donated a lot on Kickstarter. You can find them if you have a proper amount of Perception, or when completing a quest in a given location.
During the free exploration, you cannot forget about the omnipresent radiation. The bottom-left corner is the Geiger counter that displays the current radiation levels. Apart from the flickering hand, also the characteristic cracks inform you of irradiation, which you can hear. You can tell the irradiated fields, on the map, by radiation trefoils. Note the numbers on them. They symbolize radiation levels and how much protection you need to cross the field safely. So, the field with the radiation levels of 4 require rad suits with the protection level of , and the ones irradiated at the level of 2, those with protection of 2. In the equipment window, you can look up which type of suit you are currently wearing. You can find better ones at shops, while progressing in the main storyline and sometimes also in the stashes around the game world. When the party is staying in an irradiated area, without proper protection, it will keep loosing health with each passing second You should then cross the irradiated area quickly, in hope that you can make it before you die. You should then not waste your time to stop and heal - during your exploration of the world map, you can use first-aid kits, but this will stop the party so, this gives you nothing.
Also, during the exploration of the map, you will be running into random encounters. Most frequently, these are the attacks of raiders or vicious animals. You can avoid such fights with sufficiently high levels of the Outdoorman skill. Sometimes, these are non-threatening situations, such as caravans.