Generally speaking, ASL sentences follow a “topic”, “comment” (predicate) arrangement with many other variations and specifications – sentence specific. I’m not going to define these because when it comes to signing with your baby, it doesn’t matter. This isn’t meant to insult the language, I’m very grateful that I can borrow it for my needs, but I’m also not going to overly complicate things just for the sake of it. If you are keen on learning more about ASL or continuing it through toddler years, then you should definitely pursue this topic further. There are many closes on offer both online and likely within your community that can help you get along with conversational ASL.
The reason I’m making note of this is because you might hear a quip here and there about your ignorance to rules. Without being rude, try to tell your critic to park it. You can remind them about your true intend with baby sign and that you are doing it to benefit your hearing child. There’s nothing wrong with this – at all. For now and for the sake of simplicity for you and your baby, just use the words as “labels” and follow the same grammar as you would when speaking English. Using proper English grammar and signing words as you go while also using proper ASL grammar is entirely impossible (they just aren’t the same). When our goal is to raise a verbal baby, then we shouldn’t make apologies to our tactics – eventually our babies will talk and they should understand the grammar of English. In most cases anyway, your baby isn’t going to couple words together until they reach about 18 months when verbalizing is taking a much stronger role in their lives. Most of what a baby says before that is just a “topic” anyway, so there’s not a whole lot of worry should you decide to carry ASL forward.