Need help re pronunciation of some vowels

Hi all 🙋‍♀️ I’m about to teach me the basics of thai language (at least as much this is possible). However, there are three vowels and I do not get, how to pronounce them. Do you know some english words, which contain such sound? On the last picture: its the one, wich looks little bit like a questionmark, which confuses me. TIA to all your support.