You are correct that you don't pay taxes until you withdraw on tax-deferred accounts such as IRAs, 401ks, 403bs, etc.
If you have received a 1099-DIV and a 1099-B, however, then the account is a taxable account (not an IRA, 401k, etc)
You do need to enter them. Here's how:
Input your 1099-B at:
Federal Taxes > Wages & Income >
Scroll down to Investment Income, then click Show More
Select Start next to Stocks, Mutual Funds, Bonds, Other
(at the bank logo screen, scroll down and select "I'll type in myself")
Input your 1099-DIV at:
Federal Taxes > Wages & Income
Scroll down to
Interest and Dividends and click Show More
Select Start next to Dividends on 1099-DIV