work from one side to another, so you only get one odd edge. follow the instructions on the packet of paste unless your using copydex.
NO NO NO NO
Do not work from one side to the other. Work from the Middle & make sure the main Pattern/Print is in the centre of the wall.
Especailly as its one wall, I suspect its to be a feature.
If its a whole room, then start in the centre of your main wall.
Egg is right, you cannot trust either side wall to be straight. Professionals start in the middle.
Get a bit of string with a weight on the end and start off with a line down the wall, half a sheet away from the centre Then paper outwards in both directions. This will give you an equal edge on both sides. By starting like this any drift in alignment will be less of a problem too than starting at one side. The issue of the paper in the corners not matching is only a problem if you have a distinctive pattern and are doing more than one wall. Surprisingly very few people notice.
As to putting the paste on I suggest doing it in one strip widths, if the wall is dry and bare then it will suck in the water from the paste and you will end up with problems.
TBH its much easier to do if you are using two complementary papers with a border along the centre but the above is simplest with a single paper.