Had a few minutes to give you some starter code which is meant to show possibilities, not a solution directly.
In _Layout.cshtml
<div class="container-fluid border border-warning">
<main role="main" class="pb-3">
@RenderBody()
</main>
</div>
index.cshtml
@page
@model IndexModel
@{
ViewData["Title"] = "Home";
}
<style>
.container-fluid {
padding-right: 30px!important;
padding-left: 30px!important;
}
</style>
<div class="row">
<div class="col bg-light">Left 1</div>
<div class="col-auto">Right 1 . . . .</div>
</div>
<div class="row">
<div class="col bg-info">Left 2</div>
<div class="col-auto float-end"> . . . . . . . Right 2</div>
</div>
<div class="row">
<div class="col bg-light">Left 3</div>
<div class="col-auto text-end">Right 3 . . . . . . . </div>
</div>
<div class="row">
<div class="col-8 bg-info">Left 4</div>
<div class="col-3 text-end">Right</div>
</div>
<div class="row">
<div class="col-sm-9 bg-light p-3 border">
.col-sm-9: width of 75% above sm breakpoint
</div>
<div class="col-3 bg-light p-3 border">
.col-3: width of 25%
</div>
</div>
<div class="row">
<div class="col-sm-6 bg-info"><p class="float-start">left</p></div>
<div class="col-sm-6"><p class="float-end">right</p></div>
</div>