You'll see lots of people tell you to take your time, and you need to take this advice along with all the salt available in the ocean!
Do your research as a beginner. If done properly and patiently you have about from 3 to 8 weeks to fully cycle a tank. During that time, learn about your equipment, or plan out future purchases. Lights and live stock, proper filtration. You don't need to have everything, you just need to have the right things for what you are trying to do.
Avoid purchases that you think you will upgrade real fast, selling old equipment is a lot more daunting than just posting on the forums.
Water chemistry is basically the game here. Whatever you do you want to obtain pristine water conditions for your fish or coral. They are after all living organisms. You wouldn't want to be constantly breathing in smoggy air from Los Angeles Highways or Beijing, don't subject your fish to a stressful life.
From my experience, taking these precautions will greatly lead you down a path where you don't have to restart your tank. Well established tanks take time, but you can destroy it in an instant. Even something as simple as having fish or clean up crew dying and decaying in your sandbed can cause unnoticeable problems.
Last but not least, have fun! just don't check your bank statements.
