Import Pack???

Hello,yesterday i downloaded Unreal engine 4 and today i buyed 2 "packs,one is named “grass pack” the other is named “landscape stamps”
i tried adding the grass pack to my project,let it download etc and opened unreal engine and the project,sadly after long searching i haven’T found a way to actually use the stuff yet and i hope i didn’T just loose 40 euros and somebody here can help me

so my question: how do i use the pack

Once you buy a package, they go to your Vault area located in the Menu at left called Library. Search there for the package name you have purchased and them you have few scenarios for some packages: some shows a button Add to Project, others a button Install to Engine, others a button Create a Project. For the Add to Project scenario, you need to create a project 1st with the engine version which matches the package and then select in the page which will open the project you have created previously. For the Create a Project scenario, once you click the button and it will ask for the project name you want to create. The Install to Engine scenario, are for plugins, which once you install into the engine, they will be enabled inside your project with the Plugins menu opened.

I hope it helps! GL!