Fires serve many purposes and can be created in various ways. The basic way to start a fire is by kindling, steel and flint. To start a basic campfire, you'll want to find an old fruit tree (you can discover the age of a tree by right-clicking the tile that the tree is on and selecting examine). The reason you want to use the fruit trees as opposed to, say oak or pinewood, is because they have the least amount of wood and are good for skill which is a nice bonus since improving this skill will make things faster later on.
Once you've found a nice [[tree]], activate a steel [[axe ]] (at this point you should put it in your right hand by dragging and dropping, in case you get into a fight with a wild animal) and right-click the tile the tree is on, the same way you examined it. Click the Chop Down option, and you'll begin to do damage to the tree (the amount of damage can be viewed by examining it). You may need to repeatedly chop down the tree to get it to fall.
After your tree has been felled, there should either be a log or a felled tree in the tile where the tree once stood. If there is only a log, right-click it and take it. Otherwise, right click the felled tree and select Chop Up, which will produce a log each time until it disappears. You should only require one log, so take one.
Here is where you can either take the skill-improving route (recommended), or the quick route. For both routes, you will need to activate your carving knife.
If you chose the skill-improving route; right click a [[log ]] and hover over the Create sub-menu, then choose a random option and keep repeating that after each action is completed until you have a pile of wood scrap in your inventory. If you have more than one scrap, there are 2 options: right-click the entire pile and choose the Combine option (which can combine up to 10 or 11 scraps), or activate one scrap, right-click another scrap, and choose the Combine option.If your wood scrap has a weight value of 1.5kg (the standard measuring unit, if you don't have this much then make more scraps and combine them), activate your [[carving knife]], right-click the scrap, hover over the create menu and choose [[kindling]]. Keep repeating this process until you have a kindling.
Activate your carving knife and right-click the pile of wood scraps that you just combined. If it is heavier than 1.5kgs then make kindling out of it. Repeat this process until you have at least one kindling.