Do I need to enter ESPP transactions?
Only if you sold stock that was purchased through an ESPP (Employee Stock Purchase Plan).
In that case, the sale will be reported on Form 1099-B, which you should receive from your brokerage around tax time (early February is typical). Simply enter your 1099-B to report the sale on your tax return.
If you merely purchased (but did not sell) ESPP shares, there's nothing to report.