You are welcome, Harmony. The Russian word for 'timer' is 'таймер'. Я неправильно установила/поставила/выставила таймер.

Wow, thank you for specifying. I didn't know there we're such differences. It helps a lot. I wanted to say "I had set the timer incorrectly."

If the third sentence in English is 'I have a university degree', then it is 'У меня высшее образование' in Russian. Normally, the word 'степень' (usually 'ученая степень') is only used in this context if you hold an advanced university degree such as Ph.D. or D.Sc. As for the third to last sentence, it is vague because 'хронометр' is an instrument that accurately measures time and, paired with the verb 'делать', the phrase takes the meaning of 'to manufacture chronometers'. If you meant timekeeping, you would say 'Я неправильно делала хронометраж' (it is not particularly understandable without more context).