bump

Or a long ramp?

You're right: you do need an expert. Go to an architect or structural engineer.

You aren't going to get free help on a project this in depth, you're going to have to hire someone. No one is going to be willing to take that risk.

The plan shows a step. As all plans will do. You must have the finish grade soil sloped away from the house 1/4" per foot for a minimum of 10' around the home, and starting at least 6" lower than the siding. 12" is better. The construction grade will be even lower, as it will need to be topped by topsoil during the landscaping phase. If you need a zero entry home, that is accomplished through ramps on the exterior at the end of the build.