And remember to relax your hand. Beginners have a tendency to really clamp down on a chord. (I just made this chord, and byjeez, I ain't letting it go till it squeals).
Let your hand relax at least every minute or so. Open it and gently shake it. What you eventually (hopefully sooner) learn is to press down with the minimum force needed. Your hand needs to learn to float between chords.
If your fretting hand feels sore or tired, stop. Learning guitar is as much a physical exercise as a mental one.*
Good luck, and know that we all went through this initial phase.
Rich McCarthy