How do I make all the images of a carusel have the same measurements?

as simple as adding a style to the images either by linking the css file or putting the styles directly into your html file example:

 <style>
 /*aqui le dices que las imagenes que estan dentro de la clase "carousel-item" todas tengan la misma altura y ancho*/ 
   .carousel-item img{ width:400px; height:400px;}//esto es un ejemplo aqui pones la medida que se adapte a tus nececidades
 </style>


<section id="carousel">
<div id="carousel-home" class="carousel slide" data-ride="carousel">
    <ol class="carousel-indicators">
      <li data-target="#carousel-home" data-slide-to="0" class="active"></li>
      <li data-target="#carousel-home" data-slide-to="1"></li>
      <li data-target="#carousel-home" data-slide-to="2"></li>
      <li data-target="#carousel-home" data-slide-to="3"></li>
      <li data-target="#carousel-home" data-slide-to="4"></li>
      <li data-target="#carousel-home" data-slide-to="5"></li>
      <li data-target="#carousel-home" data-slide-to="6"></li>
    </ol>
    <div class="carousel-inner">     
        <div class="carousel-item active">
          <img class="d-block w-100" src="img/Marina Pez Vela.jpg" alt="Marina Pez Vela Quepos">
            <div class="carousel-caption">
            <h1><p class="text-body bg-light">Marina Pez Vela</p></h1>
          </div>
        </div>

          <div class="carousel-item">
            <img class="d-block w-100" src="img/marinapv.jpg" alt="Marina">
              <div class="carousel-caption">
              <h1>Marina los Sueños CR</h1>
            </div>
          </div>