If you see there it discusses about arba minnim and it says that a minor cannot own anything.
My question is, what age is a minor?
-13? -20? -6? -Married?
The age/status of minor calls forth a general rule but occasionally depends on the situation. The standard is that a boy is a minor before his 13th birthday, and a girl is a minor before her twelfth. The talmud explains some reasoning here (as rashi does on Erchin 13) and there are discussions of outlying examples testing the age vs. the reasoning, but those are simple to remember ages. For certain laws during biblical times, a person had to be 20 years old (serving in the army) or 25 years old to be considered a full fledged participant (like a Levite) but before that time, one was not a "minor" in the legal sense AFAIK. Other ages might have conferred a particular status under Jewish law but none that specifically effected the label of minor/adult.
The talmudic term is "koton" and it refers to someone who generally is under 13 years old (I recall one legal wrinkle which includes boys under 13 years and 3 months as minors in some sense but not lulav).