Hello Oscar0822,
I presume by "child" you mean under 13. For under 13, see Legal - iCloud - Apple
"I. REQUIREMENTS FOR USE OF THE SERVICE
A. Age. The Service is only available to individuals aged 13 years or older (or equivalent minimum age in the relevant jurisdiction), unless you are under 13 years old and your Apple ID was provided to you as a result of a
request by an approved educational institution or established as part of the Family Sharing feature by your parent or guardian."
So basically a child under 13's ID has to be set up by a parent under Family Sharing and Family Sharing requires Apple hardware to set up. *
Even for over 13, if you want to have control over what the child does, this has to be done as part of Family Sharing which requires.
*I'll just add at this point that Apple does talk about setting up a family group and "Family Sharing" on Android in this document: Use Family Sharing with Apple Music on Android - Apple Support However, that may strictly be in the context of sharing an Apple Music family subscription and not extend to other Family Sharing features.