How do I keep the dirt from covering my sidewalk?

Install a border of some sort to keep the soil from eroding. They have plastic benderboard type by the roll. Or you can do a decorative border with stones, bricks, etc. Here are some sites with ideas from inexpensive to bit more.

https://homesthetics.net/17-simple-cheap-garden-edging-ideas-garden/

https://www.ltdcommodities.com/Garden---Outdoors/Outdoor-Decor/7-Ft.+Flexible+Border+Fence+Sets/prod2500168.jmp?mrkgcl=887&mrkgadid=3206702984&ukwcid=+&cid=GooglePLA-25001682440571&product_id=25001682440571&adpos=1o2&creative=194094350112&device=t&matchtype=&network=g&gclid=Cj0KCQiA_s7fBRDrARIsAGEvF8Rpdu5-M76NLzXnZ1Kt8iQx0iFbDaRfk70rJD_gtnmv8vlF7CpqiPYaAtcrEALw_wcB

https://diygarden.co.uk/landscaping/garden-edging-ideas/

You could put a border up and plant flowers. Or plant grass or sod to hold it in.

Hi Vallery,

Since your yard is above the level of the sidewalk, the dirt and etc naturally flow downhill due to gravity and the forces of nature. What you can do is put in a barrier along the sides of your sidewalk that is above the height of the yard, this will stop the flow of the stuff that is coming onto your walkway.

They have these lip like liners for edging gardens, sidewalks, and other projects where you want to prevent one side from coming onto the other side.

They come in various heights and are available at DIY stores and very probably Amazon.

Pavers higher than the dirt