A common, sensible progression is: an open cup (with help) from around 6 months alongside weaning, a 360-style cup that trains lip position without a hard spout, then a straw cup once your toddler has the motor skills, moving away from hard-spout sippy cups sooner rather than later since they can affect the same oral development that dummies do if used for a long time.
You don’t need every stage of cup — many toddlers skip straight from an open cup with help to a straw cup with no issues. Buying one of each stage "just in case" is the most common overspend in this category.
For travel and the car, a genuinely leak-proof cup matters more than the training-stage features, since spills in a car seat are the actual daily pain point, not the cup’s developmental credentials.