1) If by mistake I recite namaz before the actual time what should I do?

2) I recited namaz 1st rakat Alhamd and surah qadr. Now second rakat I have to recite Alhamd and surah ikhlas but by mistake I start reciting surah qadr again only one word I recited then I realized, so can I stop say Bismillah and recite surah ikhlas ?

1- Repeat that namaz
2-Yes you can.