this is a nice question , you can do this in multiple ways First
<View>
<Text>
Hi this is first line {\n} hi this is second line
</Text>
</View>
which means you can use {\n} backslash n to break the line
Second
<View>
<Text>
Hi this is first line
</Text>
<View>
<Text>
hi this is second line
</Text>
</View>
</View>
which means you can use another <View> component inside first <View> and wrap it around <Text> component
Happy Coding