Why does this keep happening to my thread?

My seeing machine keeps doing this about every thirty seconds or so while seeing... It stops and the string is stretched and the top gold part of the picture, that thing keeps "catching" the string somehow so I have to pull it out of there and re-thread every time.... 
I'm kind of a beginner and have no idea what the use of that gold part is anyways, and now it keeps causing me problems... 

Lib.rare.ian2021-03-15T18:36:55Z

I second drip's answer: guide the upper thread through the maze of guides on the machine while the presser foot is in the UP position in order to catch the thread through the upper tension discs, which are hidden inside the head of the machine. They are open (pulled apart) when the presser foot is UP, and closed (pushed together) when the presser foot is DOWN. If they are closed, the thread can't pass between them, so the upper thread tension is messed up.

drip2021-03-15T14:02:11Z

It isn’t threaded correctly. 
The thread is catching and when you sew the thread  is pulled and breaks.First check the spool of thread ( not string) Some have a little tiny notch that the thread is hooked into when you buy it.  Sometimes the thread can catch on that notch while you are sewing. Flip the spool of thread so the notch is on the other side. Every now and again I get a spool that does this. Thread your machine with the pressure foot UP!! You can not catch the thread in the tension in if your thread it with the pressure foot down. Hard to tell in the photo but I assume your tension gears are behind the gold part.  I think this is your issue, not catching the thread in the tension gears correctly. Once it is threaded and through the needle, while the pressure foot is still up, gently pull the thread back behind the needle, it should flow smoothly. Not loosely and  not tug. Hold that thread tail and manually turn the hand wheel and pull up your bobbin thread, pull both thread tails behind the needle. Then put in your fabric and lower the pressure foot, Hold  on to these two tails for the first few stitches. Also make sure you wind your bobbin with an even speed. Don’t slow down and then speed up. Find a YouTune on how to thread your machine. 
Re read your manual. 
if you are having problems sewing  the majority of time it is because the machine isn’t  thread correctly. Upper or lower thread is wrong,

I have sewn for over 30 years and still, on occasion, have to re thread my machine. 

Take a price of scrap fabric and sew on that first. Make sure it is sewing properly before putting in the fabric for your project.