1 노력하다 and 애를 쓰다 are quite similar. Both expressions' meaning is "making efforts." 나는 로봇을 만들려고 노력한다(애를 쓴다). = I make efforts[try] to make a robot. To talk about a small difference between the two, I'd rather say "애(를) 쓰다" sounds more elder. Actually teenagers or 20s rarely use "애를 쓰다" when they have casual conversations. "노력하다" is used more commonly. 2 시도하다 means "just giving a try." 나는 로봇을 만들려고 시도한다 = I try making a robot. Hope it helps! :)