you are beautiful-- tum sunder ho , (आप सुंदर हैं,)
he is handsome---wo acch dikhta hai (can use "sunder" also)( वह सुंदर है,)
i love you--- (mai tumse pyar karta hu) (मैं तुमसे प्यार करता हूँ,)(if she is saying then we will use "karti" if he is saying then will use "karta"
i love your shirt--- mai tumhaari shirt se pyar karti hu,(but we uses this sentence as(mujhe tumhaari shirt acchi lagi),
i am glad to hear that--mujhe wo sun ker khushi hui "or mujhe wo sun ker accha laga( मैं यह सुन कर खुश हूँ,)
thank you--dhanyawaad (शुक्रिया)