Nope, that'll work! You can add or remove devices to/from the HomeKit and Alexa integrations at any time, and there is no problem just adding one or two devices at first before adding more.
Here is a topic another community member created with some tips for users migrating from other platforms. You may want to take a look:
If you run into any problems or have any questions, lots of people here are willing to help (sort of like the ST community, from which many of us came). Welcome, and good luck!
