I have finished adding my crypto buy and sale individually, and I can't seem to get to filling it because turbotax is asking about cost or base, date of sale/purchase

Yes, in order to calculate Capital Gains/Losses for Schedule D, you need to enter the Date Purchased/Date Sold (to determine whether short-term or long-term,  which are taxed differently).

You also need to enter what you paid (Cost Basis) for your crypto, and what you sold (or traded) it for to see whether you had a Gain/Loss on the transaction.

You can report transactions in summary for the year as investments, and use 'various' for the date of purchase and 12/31/2020 as date of sale. Keep good records of your transactions.

Click this link for more info on Crypto Transactions.

This link has a detailed discussion on Entering Cryptocurrency.