Need advice! First time mom!

Mesa
I found out this morning I'm pregnant! My fiancée returned from deployment in Afghanistan and we decided to try and have a baby! I got my IUD taken out July 5th, had my Period on July 7th and just today a positive!
What's the first steps I should take?
I know not to announce until after the first trimester!
When should I get my first ultrasound?
I'm worried about having a miscarriage...is it really that common? A friend told me 50-75% of the time people miscarriage :( 
Any tips are welcome and much appreciated!