Warrior 1 pose or virabhadrasana 1 is a common pose in a standing series in hatha yoga. It makes a great transition pose from various standing postures including warrior 2 and triangle though the foot alignment is slightly different.
Remember that as you attempt the pose the shorter the stance, the closer the feet are to each other the easier it will be. You can always scoot the 90 degree foot out further if you need more depth. Align the hips so your guns face forward and lift the spine. A 90 degree knee gives you the workhorse in your quadriceps and builds strength in your lower body. Pull the belly in and lift your spine. Long slow breathing through the nose while retracting the neck will complete the alignment through your spine and relish the sense of space you create.
Lift your arms in any position you like but slowly work them up above you for extra lift. No slouching. Use your breathing to massage your body into position.
Try going through several poses in sequence including this one. Triangle and warrior 2 are good options.