You are correct that ASL and English are not the same, ASL has its own grammar and ways of getting a message across. Things like facial expression, hand placement/hand shape are all a part of the language in addition to the signs. Like others have said, it’s best to learn from Deaf people, whether that’s a teacher at a school or a creator making YT or TikTok videos. For one, they know the language best as well as the culture, it’s also important because when hearing people are teaching ASL, especially in places like schools, they are taking away potential jobs from Deaf/Hard of Hearing people. I’m hearing, but currently taking ASL at my community college, so I’m explaining what I have heard from people in the Deaf community, both from school and the many Deaf creators I follow on TT. I’ve also been using an app called InterSign which has some good lessons, though maybe not always super specific to working at Starbucks :) but it can definitely be a tool to help learn some basics.

Just don't tell Deaf people babies you know use baby sign. We constantly hear that and it's rude. Babies stop using sign as soon as they can speak comfortably and never use it again. ASL is a difficult language that takes years to learn. I constantly hear that people "have always wanted to learn sign". No one ever does, because it's hard. It's a real language and there's a culture and history. ASL is not word for word translation of English. There are different types of ASL. Honestly most hearing people are so bad at sign that it's easier for Deaf people to just try to understand them in the ways we are used to doing. It's really best to take classes with a Deaf teacher. Baby sign is not different signs. It's signs that are in ASL, like "more" or "light". It's just not awesome to connote baby sign with ASL that culturally Deaf people use.