Short answer: for the first year, choose a few well-made, mouth-safe toys that match the current stage — sensory play, then grasping and cause-and-effect — and skip toys that need a screen or do the playing for the child.
How play develops in year one
Baby play follows a predictable path: exploring with the senses, learning to grasp and pass objects, then discovering cause and effect ("if I drop it, it falls"). Each stage builds on the last, so the best toys are simple enough for the current stage but open-ended enough to keep up.
4-6 months: sensory first
Look for soft, graspable shapes with contrast and gentle texture. Mouthing is how babies explore at this age, so natural, child-safe materials matter most.
7-9 months: grasping and cause and effect
Babies begin reaching, grabbing, and dropping. Toys that respond predictably — that rattle, roll, or come apart and go back together — help them learn that their actions matter.
10-12 months: first actions and standing
Interest shifts to stacking, posting shapes, and pulling up to stand. Activity cubes, simple stacking toys, and sturdy wooden walkers match this stage. Always supervise, and follow the manufacturer's age guidance for each product.
What to skip
Skip toys with many small parts, loud electronic noise that does the playing for the child, and anything marketed purely for display. A few toys the child can really use beat a room full of extras.