not only broaden your horizon but also can make you confiden

It can not only broaden your horizon but also make you confident.
confidence是名词,让某人怎么样,怎么样是宾补用形容词
如果一定要用名词的话,前面的make换成：strengthen
另外,没有主语,broaden 和 make 这两个动词都是受制于can（即能拓宽、能让你）,因此将can提前到not only 之前,这样他们就能share这个can了