We use wish + (person / thing) + past simple to talk about things we would like to be different in the present / future (but which are impossible or unlikely).
After wish, you can use was or were with I, he, she, and It, e.g. I wish I was / were taller.
We use wish + (person / thing) + (would / wouldn't) to talk about things we want to happen, or stop happening, because they annoy us.
You can't use wish + would for a wish about yourself, i.e. NOT I wish I would..., I wish we would...
We use wish + past perfect to talk avout things that happened or didn't happen in the past and which we now regret.
If only is sometimes used instead of I wish in certain situations, to express deep regret, e.g.
If only I had worked harder at school (I wouldn't have such a boring job now).