Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You have to compete for kisses (きそ) from that boy/girl you like. Imagine yourself doing this, competing with a rival.
The children raced over to the new teacher.
Tofugu is so unique that there is nobody else to compete with. They are the so-called sole winner.
Koichi and Viet competed with each other to demonstrate their prowess at the annual Kendo competition held in the Tofugu office.