If you are a very high income earner you will see a very sizable cut to your taxes. If you have a large estate that will likely pass to your children tax free. If you are a middle income earner you will see a modest-moderate cut to your taxes (potentially a more substantial cut depending on what "tax loopholes" he wants to close). If you are a low income earner you will see little-to no change. If you own a business that outsources manufacturing or you have locations overseas you might quite possibly be totally fucked, depending on what he intends to do. In fact, even if you simply buy every day things that happen to be made outside of the US your business can be hugely impacted. Unfortunately all we know is he wants to tear up trade deals but we don't have the details on what that exactly means. I am extremely concerned about his position on this.
Now, we know that he also wants to increase the military budget, deport Mexican immigrants and build a wall. Couple those expenditures with massive tax cuts and we will add trillions to the deficit (his growth assumptions are the stuff fantasy tales are made of). Assuming he gets everything he wants, of course, this is completely unsustainable. In this scenario we would very likely see massive cuts to offset the dramatic reduction in revenue. He of course doesn't assume there will be deficits, which IMO makes him intellectually dishonest and/or totally incompetent (my guess is both), so he doesn't talk about spending cuts. But given everything he's said on these issues my guess is that the cuts will come in the way of our social safety net, and it would be a devastating hit too. The only other option would be to raise taxes back up (passing a massive hole on to the next president) or massive cuts to military spending, which we know isn't happening.
In summary, there will be a huge benefit to the wealthy and a more modest benefit to the middle class, but it is all short-term. The long-term harm could quite possibly be history changing bad depending on what he wants to cut and what he would do with trade deals.