OK. If you want to make wheat flour tortillas (they are the typical Tex-mex tortilla beloved of US and British Mexican restaurants) you would be better strating from scratch.
You need 1kg of plain white flour, 2 tps of baking poweder, a pinch of salt ad 300g of lard (or vegetable oil), and a cup of hot water.
Mix the dry ingredients. Then add the melted lard or oil and mix, then add water bit by bit until you make a dough like ball. Take golf ball sized bits and flatten into circles (you can get presses that make life easier, but you might need a specialist shop). Cook on a very hot skillet or something similar.
Tip: you know when to turn them when the hot air inside makes the tortilla rise inside to look like a tent.
Maize tortilla, the Mexican (not Tex-mex) staple is easier. You need 1 kg of maize flour, a pinch of salt and hot water.
Just add water to the dry ingredients bit by bit until you get a dough. Then follow the same instructions.
It's not diffiult, but there is definitely a knack to it. You first effort will probably be a bit of the thick side.
Failing that, at the bottom of my street in Mexico is a little old lady who sells masa (harina or maÃz) at a very reasonable price. It might cost a bit on the sirfarre though