If you are a new player and lost your home, do not panic. Here are the steps to get back home.
The first thing that you should try is the /back command. This command teleports you back to your last known location. If you were recently at your home, you should be able to use this command to get back there.
The next thing you should try is the /home command. This command teleports you back to the location where you set your home. After finishing the tutorial, all players automatically have their homes set at the location which they randomly teleport to, so this should be relatively close to where you want to go.
If you still cannot find your home, you may be able to find it from your claim coordinates. When you first place down a chest, a claim is created for you, and its coordinates can be found with the /claimlist command. You can view your current coordinates with /coords and use this to find your home.
If you never made a claim at your home, you should use /map to see if you can find the home on the map.
If all else fails, you can open a ticket on Discord and request for your home location. As long as you tell us what specific blocks you placed or broke at your home, we should be able to find it.
After you have found your home, you should use the /sethome command. This will allow you to easily return back with the /home command.