This is typical of a front porch with brick columns that do not go to far into the soil.
You will need to replace the piers , possibly one at a time.
My suggestion is to get a professional to help you with the basics of where to start. The issues with this porch could be beyond what you as a homeowner sees. There may be issues only a professional will notice like pests or parts pulling away or not supported correctly. For the money it would be a no brain-er to get you to know what to do first or at all.
Typically this is an easy labor intensive pay attention to load transfer repair, however with it being old some wood may not bend like it used to. I would hate to here of a collapse when you are working on this.
Maybe you can hire someone to work with you on the project ?
Never hurts to ask. Check out your local lumber yard for a candidate or two.
Happy and safe building.