Why is credit so important

[Bennie Hall]

So I just bought a SFH in Amarillo TX for 43k. House needs about 40k worth of work but luckily father lives there and can do most of the work which saves me about 15k. Now when finished home will be valued around 120k. Plan is to rent for around 1200 a month but I'd like to keep investing. Are my only options a home equity loan or HELOC???? Right now my credit is in the mid 600s and rising slowly but not sure if it will be in the 700s by this spring. Do I have any other options???? After purchasing the home I still have around 15k cash to invest but like to keep it as a nest egg. Any advice would be great. I also have the VA loan option as well. Thanks in advance.