Buy coin from various exchanges that my dad has an account in, I give him money, he sends me the coin (He doesnt monitor my trading its just the way I have to buy since I cant have an account on most exchanges) then when im ready to sell, I exchange my alts with exchangelly for tether, then when I want to sell the tether, I either sell it to one of my IRL buddies that my age and trades as well, or I sell it to my dad who cells it to Coinbase.
Another note: Thanks for the merits Pharmacist, I didnt think a high up member like you would be reading my thread!
I think it is a nice approach you are doing here. Working together with your Dad is great for both of you, you can use platforms that are usually only for 18+ year olds and your Dad learns something about crypto currencies. How about you put the money together with your Dad? You could do like 60/40 between you two and like that you have more money to trade. Unfortunately my friends are not so interested in crypto currencies. It would be nice to sell them some coins.