The way to block another member is to make your account private. To do that from your computer, click on your profile picture in the top righthand corner of the screen. From there, you will have access to your profile information. Under “Social” make sure that you have the slide bar turned off.
Or from your iOS or Android device, click on the “Person” icon on the bottom left of your screen. You will then see a “gear” icon in the top righthand corner. From here you can go to your profile info. From here, make sure that you have the slide bar for “Make profile private” turned off.
This will make your profile private, your activity and creations won’t be visible to the community.