Read the rules and the examples.Then make sentences.

We use this/these for things near us.
We use this in the singular and these in the plutal.
we use that/those for things far away from us.
we use thar in the singalar and those in the plural

Если это то что я понял, то так3  This is a digital camera.4  These are watches.7  Those are trainers.8  That is a skateboard.