First, what country are you in? The device selection does vary.
Second, it will probably be more practical for you if you use one smart master switch, one auxiliary switch to go with the master, and one motion sensor. But still use dumb bulbs. Unless you are in a rental and you are not allowed to change the light switches. That way you will still have switches on the wall that work the way you are used to but you also be able to use the motion sensor. And you will probably save a little money because smart bulbs are expensive.
As far as which motion sensor, there are a lot of good ones, and again it depends on which country you are in. Different people like different ones for different reasons.
Although there are many different ones to consider, if you are in the US, one of the most popular is the Lowe’s iris, which is often on sale and you can use a regular Iris coupon as well. This is a good fast motion sensor, so very suitable for triggering lights as you walk into an area. But it’s only available in the US, not the UK.
Following thread discusses all the different features that different sensors might have and why people might choose one over another if you’re interested in that level of detail: