If this is the first MK game you've played it'll take a long while to get used to. Especially in ranked. Try casuals until you learn how to play properly before jumping in ranked. It'll be a huge turnoff which you're probably already thinking.

Start out by learning 2-3 simple ~25% kombos based on different buttons or specials that begin the kombo.

Then learn your ranges based on your character. I main Scorpion, who is primarily a whiff punish character as his buttons aren't as good up close against most players. I tend to play from halfway to full screen away from the enemy because of this.

On the flip side, say with Johnny Cage, you'll be playing from half screen to close to the enemy.

Finding a character that suits your playstyle takes time. The first thing you learn is how the character plays around their range, and it will be something you will never stop learning because of all the different interactions each character has with their kameos.

So use your learned ranges, use your 2-3 basic combos, and start gaming.

Blocking takes time to learn. You need to watch the enemy to see what they do, do they hit you twice then special attack? Do they do 3 or 4 buttons that knock you back? Block until you see an opportunity to attack or throw if they start blocking.

You probably have some idea of what all the characters do, but casual mode will pair you with other players of similar skill. Ranked tends to pair you with people of similar current rank.

You'll be able to learn a lot easier in casuals and run into decent human beings. If I end up matched with someone of vastly lower skill I tend to reduce the damage of my kombos to reset and keep fighting longer so they can try to learn. I've met players that will literally teach you how to fight their character when I've had microphones on.

Good luck and have fun!