For a $70,000 house, you will need a down payment of $14,000. The $1000 won't even begin to cover closing costs, which will run you another $3000 or so on top of the $14,000. Keep saving and working on your credit score. You won't be buying a house next year.
TO answer you other questions, a fixed rate mortgage is one that does not change over the course of your loan. If you take out a loan at 4% right now, it will remain at 4% for the next 15 or 30 years, depending on how long your loan is for. Even if interest rates skyrocket a few years from now to 15% (which was common in the 1970's by the way), you will stay at 4%.
An adjustable rate mortgage readjusts each year on the anniversary of your loan. If you take out your loan in August, it will readjust every august. If interest rates rise, so does your loan, but if they go down, so does your loan. Right now, adjustable rates mortgages are not worth the risk since the interest rates really have nowhere to go but up. Most have a cap, however, and can't increase more than 1% per year or more than 5% in total. If it starts going up, you can always refinance to a fixed rate loan, but you will have to pay closing costs again.
General rule of thumb is 3 times your annual salary is what you can afford, so the $70-80K range is fine. Your problem is going to be not having a down payment. Years ago, down payments weren't required, but now they are being required more and more. Even if you can find someone who will write you a mortgage and not require 20% down, you will end up paying PMI, which is an insurance policy that protects the bank in case you default on the loan.
When you buy a house and have a mortgage against it, the bank doesn't want to risk losing the house to fire or tax liens, so they pay the insurance and property taxes for you. This is included in your monthly payment. That is your escrow account - it is money set aside by the bank to pay your tax and insurance when it comes due. Small adjustments are made each year to account for an increase in premium rates and taxes, so if your house payment is $748 and you have a fixed rate mortgage, that doesn't mean the payment will stay $748. It will usually increase over time. I have a house that is 19 years old. I bought it new. Over the years, the mortgage has gone from $484/mo to $608 - the difference being insurance and tax. The insurance figured into escrow is your homeowners. The banks just are more comfortable paying it themselves than taking the risk of you missing a payment and the house burning down (or you getting mad at them and setting fire to it.)
Egress windows are required in all legal bedrooms. It just means the window is operational and can be opened and is so many sq. inches - in other words, big enough to crawl through it the house catches on fire. You may have a house that has a 4th room that could be used as a bedroom, but if it's in a basement and doesn't have an egress window, they can not advertise it as a 4 bedroom house. They are not mandatory as you can use the house however you want once you move into it - it just makes a difference in how it is advertised and taxed (more bedrooms, higher value, higher taxes).
Hope this helps.