A couple of months ago when my puppy Lakota was more of a puppy, she did not like to be outside alone without me...even tho my Boxer would be out in the yard she did'nt want to go out away from the front porch to poopie or pee. It took time and patience, but she got better and better with it as the days went by. I would start by letting them both out and my Boxer would always go off on her own like she normally does leaving Lakota alone sitting on the porch. I'd watch her from right at the door, hiding a little bit so she could'nt see me. She'd start to whine and cry and when she did that I'd let her until I noticed that she quiet down and s soon as I saw that behavior I'd open the door and praise her. Then to show her that she could actually go one step further and venture into the yard I'd go with her further and further, and before I knew it she was walking away from me and walking out there on her own. Takes alot of time and patience, but remember to reward immediatly the good and set them up for success everytime.
Oh guess I should also add that everytime I was with her I'd say "go pee-pee" when she peed and "go poo-poo" when she pooed. She now knows the words....so she is getting good at knowing the difference between the two and pretty much going on command when I need her too! I NEVER thought that was possible as I've heard others talk about doing it, but did'nt think it could actually work. It does...you just have to keep on her and constant repetition. Me and Lakota were joined at the hip for 3 months strait....and we still are!!! But when they are younger, it's like having a real live baby. Good luck with your new little one!