Birthday money ?

I actually have two questions the first one is if I'm given a sum of money for my birthday like a couple hundred dollars like let's say 100-400. Would I have to pay taxes on it? Around birthday time for me uncle likes to send cash sometimes it's 200 or sometimes 100. I was never taught taxes besides the if you make 6k you have to file but they never said anything about gift money.

 

 

My other question is I get two different answers but if I earn income from selling art how much do I need to earn before I have to file? Some say 400 while some say 600 I know it's self-employment tax but kept getting different answers for the earning amount. I haven't really earned even 100 but I want to ask for the future. Thank you so much ~