Future
First of all, there is good news and bad news. The bad news are there are three different ways to express future in Swedish. The good news are all of these three ways are really simple!
With the present tense, usually using adverbs
The first one is basically just present tense with an adverb to describe what time we are talking about.
Jag går till skolan om en timme (I'm going to school in an hour)
Du flyger till Stockholm i morgon (You are flying to Stockholm tomorrow)
Jag ringer dig (I'll call you). No adverb, but it's understood that I'm not doing it right now.
Although the same kind of constructions exist in English they are a bit more common in casual Swedish.
Ska
In Swedish, ska is the equivalent of the English verb will, as in I will. You might stumble upon the spelling skall instead of ska. This is often considered very formal or old-fashioned. Unless you're writing formal texts, just use ska. There is a sort of ’modal’ nuance to ska: whenever you use this form, somebody wants something to happen (or not happen). You could also say that somebody controls what is going to happen, or has decided to do something.
Jag ska gå till skolan (I will go to school)
Vi ska köpa ett hus (We will buy a house)
Kommer att
Kommer att is a bit hard to translate directly, but the closest equivalent would be going to. It is often used when making predictions about what is probably going to happen. In other words, often about things that you can't control.
Jag tror att det kommer att regna i morgon (I think it is going to rain tomorrow)
Hon kommer nog inte att tycka om presenten. (She is probably not going to like the gift)
If you happen to mix up ska and kommer att it will sound a bit strange to the native speaker but it will still be grammatically correct. Don't be discouraged by this, you will learn the more subtle differences between the two in time and with practice.
Good luck!
/ fluent 
/ learning 
/ fan of 
(bs/bl)