paypal and stubhub tax form

That sounds like you were running a business with those numbers, to go on Sch C. You can enter the income and expenses on Sch C. See Where do I enter Schedule C?

You will split up the 1099-K and enter the form twice but with the numbers apportioned. 

For example: 1099-K of $15,000. Enter the $10,000 on the business and the rest elsewhere.

• Enter just the portion that relates to the business on Sch C. 
• Enter the remainder of the income as explained by @DianeW777  here.

If this didn't answer your question, please reply with more information.

this was NOT a business, it was an accidental ticket purchase of $6K. So I sold them and managed to profit $4K. Since this is not a business and just 1 resale of tickets, should I still follow the above?

No, you shouldn't.  With this new information, the sales of tickets were personal items.  Personal items sold at a gain belong on Schedule D/8949. 

• First, enter the 1099-K information as personal item sales, you will be asked if you "sold some items at a loss or had no gain" or if "all items were sold at a loss or had no gain." Choose "I sold some items at a loss or had no gain." Then, enter how much of the $10,000 was proceeds were for items that did NOT have a gain, which is $0.
• Now, navigate to Federal > Wages & Income > Investments and Savings (1099-B, 1099-INT, 1099-DIV, 1099-K, Crypto) > Add/Edit
• Select PayPal
• Under proceeds, you will enter the proceeds of the items with a profit, approximately $10,000
• You will enter the total amount paid, which is your cost of the tickets
•  Continue on and you will be asked if you paid "sales expenses that aren't included in the sale proceeds reported on the form", here you will report PayPal fees, StubHub fees, etc.