Your sentences are mostly very good! Let's look at them carefully and make small corrections to make them even better:
Original sentence: Water birds love to live near rivers and lakes, where they can find different kinds of food. This sentence is perfect! It clearly tells us where water birds like to live and why.
Original sentence: In wetlands, birds can rest after a long journey and find safe places for their nests. This sentence is almost perfect too! But to make it clearer, you can write: In wetlands, birds can rest after a long journey and find safe places to build their nests.
Why? Because birds don't just find nests, they build them.
So the entire corrected text would be:
Water birds love to live near rivers and lakes, where they can find different kinds of food. In wetlands, birds can rest after a long journey and find safe places to build their nests.
Great job! Keep practicing writing sentences, and always check meaning and grammar.