ETF & Taxes

Long time lurker, first time poster with probably a silly question.

As the title suggests, how do taxes work with ETF’s. If I only plan on selling my ETF’s when I retire do I just pay CGT at the end? Do I have to do something at tax time every year? What happens if I buy an international ETF? How will tax work? I use Pearler and they have ‘AU’ tags on some ETF’s. If I buy one that doesn’t have that tag, does that mean it’s international which would be affected by taxes?

Sorry for the ramble, just don’t want to get stung one day! Cheers