...has been a realtor for 13-year and decided, at a young age, that he wanted to make selling real estate a career. Being raised in a large family of 9-siblings
You should not use hyphens in these instances.
We do not hyphenate such noun phrases when they are used in ordinary nominal contexts such as object of a preposition or argument (subject, object, complement) of a verb:
He has been a realtor for thirteen years.
Thirteen years have passed since he entered the real estate business.
He has spent thirteen years in the real estate business.
It has been thirteen years since he entered the real estate business.
We only employ the hyphen when the noun phrase is employed as an attributive:
... his thirteen-year career as a realtor ...
The hyphen is a courtesy to reader, making clear that the year is not the noun which ends the noun phrase launched with his but part of a subordinate constituent along the way.
Note that when we marry quantified noun phrases as attributives like this the noun loses its ordinary plurality: a thirteen-year career, a nine-sibling family.
Note, too, that when the quantified noun phrase is employed as a genitive it retains its plurality and is not hyphenated: his thirteen years' experience.
Firstly: neither phrase needs a hyphen. The use of hyphens can be tricky, but here the relevant rule is that they are used to make compound modifiers. Use a hyphen to link a modifier to another word, when the two together then modify something else.
He is well liked. ("Well" modifies "like".)
He is a well-liked person. ("Well" modifies "like", and together they modify "person".)
Both of your cases are more similar to the first example above. You would only use a hyphen if it was instead written like so:
...has had a 13-year career as a realtor. Being raised in a 9-sibling family...
Secondly: in your sentence, "13-year" (or, as it should be, "13 year") is incorrect because "year" should be plural, "years".
(Note that the example I just put above is correct as "13-year", however, because nouns like "year" stay singular when used as modifiers to other nouns.)
...has been a realtor for 13 years and decided, at a young age, that he wanted to make selling real estate a career. Being raised in a large family of 9 siblings...