The first blank option is "Performing" and second blank option is "develop"
Step-by-step explanation:
- The given sentence can be created as best parallel structure sentence as follows:
- Practicing regularly and performing frequently help young musicians acquire skill and develop confidence.
- In the first option blank, we can use both performing and to perform. But as the previous word of the sentence is practicing. Following gerund instead infinite,.
- The next appropriate option will be "develop"