As mentioned on previous posts, there are numerous factors that will give you your answer. 

My son is in his 30s and just now getting into it (even after years of listening to me :-)I'd say yes, get him started early......but do NOT do it for him.

Hi everyone I am Heidi, a new memebr of Bigger Pockets, though I have been listening to the podcasts and reading the books for years.

I did my first flip in 2002 and have done numerous since.

Listen to @Jon Smith he has provided with good insides and he is also in your market, but in summary things that you have to look at:- You have to do a rental CMA to know how is the rental around your property with similar features and size.

Sometimes it's ambiguous, but even then, why should I bother with the company that has numerous unresolved lawsuits, versus another company that is virtually the same but has none.

Search the BP for ADU appraisals to encounter numerous examples.

Some are posted to the Real Estate Events & Meetups under Real Estate Classifieds on BiggerPockets, Eventbrite, and the numerous investor Facebook pages. 

There are numerous numbers you can look at but it really depends on what your investing goals are for. 

If you are a podcast listener, maybe check out the health episodes of Impact Theory and the Huberman Lab.