The simple answer is that you only need to confess mortal sins in kind (aka lie) and number (aka twice) with a contrite heart and purpose of amendment without leaving out other mortal sins. It is a great practice to also confess venial sins regularly. So you are fine just saying I lied twice. The priest will probably praise God for your brevity.
The longer answer. If the circumstances (like purpose or reason) make the sin much greater then they might need to be included. For example: telling a few white lies doesn’t merit further elaboration than just saying I lied however many times. But if you lied to your spouse about some major debt for the past five years, you might want to include some more detail. **The classic example is don’t say you stole a rope, when there was a cow attached to it. **Returning to my lying example, you wouldn’t need to go into deep explanation about the kind of debt or even the exact length of time if you can’t remember or the exact size of the debt or who the debt is to or etc. Just saying I lied to my spouse several times over the past few years about a large debt. In general the priest will ask for more details if he needs them and just sticking with kind and number is fine.
Hopefully that second part doesn’t confuse you too much.