Getting Started- need advice

I am new to this forum and the concept of investing in property. My husband and I are keen to get ahead in life and are learning the investing trade and considering our options. My question is this:

My husband and I are 30 and we have a 9 month old baby, I will be returing to work (as a teacher) part time in 2 weeks. We are keen to look at investing in property but also have plans to knock down and rebuild our home. We are expecting to spend approx. 200k on our house and are looking at doing it in the next 5 years. Our current loan is approx 180k. Should we put off investing until after we have done our home or not? We dont want to leave the house for longer than 5 years.