If you know me, you'll know that I am a terrible singer when it comes to high notes, as I struggle to use head voice, instead using chest voice. I strain to use chest voice while singing high, and my voice gets a little scratchy after a few days. Is chest voice bad for you when it comes to high notes?
If you are having to strain and your voice starts getting "scratchy" it's a good sign that you are doing some damage. This is a case where it would definitely be worth getting a couple of lessons from a good teacher to learn techniques for getting those high notes without strain
If you strain your voice or have to "belt" out while singing in chest voice, then it is better to learn from a choir teacher or someone who can help you reach those high notes. You could damage your vocal chords if you strain too much.