Suggestions on At Home No Equipment Exercises & A Question

Friends,
Peace,

In short, I was hoping to gain strength & fitness without equipment because I currently cannot afford diverse training items. This said, my peak of physical fitness included both equipment & a plan (the original P90X). Is there anything out there (hopefully, for free) that could achieve good results without equipment? Both exercises and a total body routine/plan would be helpful (I am good at following directions but not experienced enough to develop them myself).

And the other question: I have had a shoulder/neck ache for a little while now (seemingly not related to any workouts). Any suggestions on relieving this tension via exercise, stretching, &c?

Thanks friends,
God bless,
A Modern Miroku