How can I build a retaining wall around the house?

I would suggest contacting a contractor. Most will give a free estimate, and you would be able to decide if their plan is something you can execute yourself. I would suggest a drainage pipe under the ground, but you might need to check with your city/town/village to do that, and a contractor would know

Best is to slope any soil away from the house. Installing a french drain either inside or outside the perimeter of the house. This would prevent any water coming in.

I would put in a serious French Drain with catchment basins out to the street storm drains.... behind any retaining wall as it may fail if the drainage isn't there.

we have a drainage ditch next to our house too. Have you checked to

make sure the pipe isn’t clogged? I used creek rock stacked up around my flower beds We also used some of them along the sloped side of the ditch after we poured some sand to help slow the water down Hope this helpS.

i had pvc pipe with holes to distribute water. It does go out to street when heavy rain. The pipe is covered with bed rock so it looks nice.