1. Infrastructure: He never did much except for one of his weekly science fairs on it. But in the United States we have an infrastructure that needs a large upgrade. Roadways that are not well designed for today traffic. Serious Water Problems, We hear about Lead, but in many solid Republican communities, the water supply has been polluted with chemicals such as PFOA. As well improvement in our communication. This is something I don't know why Trump didn't push as part of his 100 day agenda. As a guy who likes new and shiny stuff big machines, and big buildings. This would had been an easy win for him, where he can put on a hard hat, cut ribbons, and have a clear measurable thing to show for his "leadership". This is also something that he could had bipartisan support for. Starting off his campaign as being the Deal maker.
I suspect this is because Trump craves praise, especially cheering crowds of enthusiastic supporters. Trump, himself, probably isn't interested in infrastructure repairs and upgrades because it's pretty boring stuff, and thus he doesn't expect it him to get the instant cheers that, for instance, picking a fight with black NFL players would get him. Why do hard work, when it's so much easier to pick fights with people your supporters already don't like?
2. American Jobs: Unfortunately he really turned this into a raciest agenda. However a lot of jobs (including tech jobs) are being outsourced. Where Americans are kept on board until they have trained their replacement. But could had pushed back against the American tech worker shortage, and showed the mass set of skills which could had been used.
I think this is a difficult problem to solve. The problem isn't a lack of qualified people in technology, it's really a lack of knowledge and trust on the part of would be employers. Many managers seem to want to hire people who are doing the exact same work as the job they wish to fill, and they want to pay their new employees below market rates. This is because they don't understand who can be trained to fill that role, they want to do their job and keep costs low, and if they invest in training an employee, that employee might take their new valuable skills and leave for some place that will pay above market rates. (It might be important to note that for the manager, failing to fill the position is probably "not their fault" where as training a new hire only to lose them to poaching could be "their fault") However, that's a nearly impossible goal to achieve without importing workers from (or exporting jobs to) locations that currently have a much lower local market rate. So there seems to be very little that the President can do about this, other than claim that particular visas are bad without understanding what the problems are.
3. Got things done: The idea that he was a businessman, we would think he could get things done. He however seems to lack the willingness to worry about the details, or have a complex big vision. But the idea he would be able to push this vision, like a businessman to drive change.
Trump's business dealings have been to enrich himself, he has never shown any interest in doing things for other people. In fact, his history of business dealings have been mostly about getting things done at other's people expense. I've read stories about how Trump routinely rips people off in his business dealings unless they can figure out a way to make it more expensive for him to rip them off than to behave honestly. The thing is, he was motivated to work on his business to make himself richer. Now, he appears to be only motivated to do what will get him cheering crowds and currently his supporters love it when he lays blame and insults the people they don't like, so he hasn't had to do any real hard work to get them to demonstrate their love for him.
However now that Trump became president, he only seemed do things that the Deplorable wanted,
He appears to crave adulation and cheering audiences instead of money now. And it seem it's really easy to get racists (for example) to love you (as a pubic figure), all you have to do is make a whole bunch of comments that could be interpreted as racist while refusing to condemn racists and racism. Racists have few public figures who aren't nearly universally reviled. Trump appears to have found out that being a bully and leading a mob is a lot more fun than doing actual work. So he's probably going to coast on this for as long as he can manage it.