The impact a president has on the economy is gradual and takes 5-10 years to see. Things like education and infrastructure take time to make an impact. The economy during a president's first term is largely the result of his predecessor.
If you are happy with the economy over the past 6 months, thank Obama. If a democrat wins the next election and the economy goes really well during that term, it is at that point you can thank Trump.
The share market is very different to the economy. It is based off sentiment. People feel positive at the moment. Some is Trump, some is general economic conditions.
You have to be very careful when giving credit or blame for the economy. Most of the time it does it's own thing and the government tinkers around the edges.