I bought a home last year and borrowed from my 401k, I was told I will have to pay taxes on it but it never came up when doing my return?

If you actually took a loan from your 401K you do not report it or pay taxes on it.  If it wasn't a loan then it was a distribution and you will get a 1099R for it and it will be taxable.  

But if you got a 1099R for it then it was a distribution.  They have until Jan 31 to send you a 1099R.   If it was actually a distribution you will pay regular tax on it and a 10% early withdrawal penalty if you are under 59 1/2.

You can just type 1099R into the search box at the top of your return, then find and it will give you a Jump To link to go right to it.

OR Enter a 1099R under
Federal on left
Wages & Income at top
Then scroll way down to Retirement Plans and Social Security,
Then IRA, 401(k), Pension Plans (1099R) - click Start or Update