Credit score...,

Rachel • Mon, Dec 15 • I`m 20. Been with my SO for 4 years!

So this week I was wanting to see if I could get approved for a house loan. If I am not approved does it effect my credit score? How much of a chance do I have to get approved for possibly $150,000 with a credit score of 671, plus me being a first time buyer? Thank you in advance for any information !