P
For your element, you have a couple of options to access it
<input _ngcontent-wle-c93="" formcontrolname="FirstName" mattooltip="Enter First Name" maxlength="50" matinput="" placeholder="First Name" class="mat-input-element mat-form-field-autofill-control ng-tns-c47-3 ng-pristine ng-invalid ng-touched" cdk-describedby-host="" id="mat-input-0" aria-invalid="true" aria-required="false" aria-describedby="mat-error-0">
Let's take it one by one
CSS_SELECTOR
drive.findElement(By.cssSelector("input[formcontrolname='FirstName'][placeholder='First Name']"));
XPATH
drive.findElement(By.xpath("//input[contains(@placeholder,'First Name')]"));
or
drive.findElement(By.xpath("//input[contains(@formcontrolname,'FirstName')]"));
or both
drive.findElement(By.xpath("//input[contains(@formcontrolname,'FirstName') and (@placeholder, 'FirstName')]"));
same for CSS_SELECTOR - I've shown to you the code with both, but you can access it even by specifying one attribute for your input element