Sippy cup help

My daughter is 8 months. Her dr suggested a little water in a sippy cup at her 6 month appt. I waited a month until she was 6 months adjusted so she’s been working with sippy cups for about a month.

I’ve tried 3 different cups and she doesn’t really know what to do with them. The little ezpz red cup she just tips it over and dumps the water out lol. The pink one you have to lean back to get the water to the lid and when I tilt it forward she just gnaws on it but doesn’t suck. Same for the straw one. She just gnaws on the straw. Is the normal for just starting? Should I keep encouraging all of them or stick to one?