XML Syntax for generating C# code

I am currently trying to translate part of a Java library to a C# library for using in into Unity. In this Java library some of the classes are generated from XML files, whose .xml files I have, but since I never did something like this, neither in Java nor in C#.

I have been doing some research and I have found different ways of converting this .xml files to .cs classes, but I cannot find documentation about the syntax that the .xml should have.

I tried to use the tool xsd.exe and I manage to create and xsd file from one xml file but when I tried to generate the .cs file I was propted this error: Error: Can only generate one of classes or datasets.

I then made some research and found another tool, Xsd2Code, so I tried to use it with the same .xml files to obtain a .cs file but it prompted an error complaining about the structure:

C:\Program Files (x86)\Xsd2Code>Xsd2Code.exe Vehicle.xml Vehicle.cs

Xsd2Code Version 3.4.0.32990
Code generation utility from XML schema files.

Error: Declaración XML inesperada. La declaración XML debe ser el primer nodo del documento y no pueden aparecer espacios en blanco delante. Línea 2, posición 3.
        SubType: Unspecified

        Rule:

I will translate it, since it is in Spanish: Error: Unexpected XML declaration. XML declaration must be the first node and must not contain blank spaces before. Line 2, position 3.

This are the first lines of the specific file:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:hfp="http://www.w3.org/2001/XMLSchema-hasFacetAndProperty" targetNamespace="http://www.w3.org/2001/XMLSchema" blockDefault="#all" elementFormDefault="qualified" version="1.0" xml:lang="EN">
<?xml version="1.0" encoding="UTF-8"?>
<traciClass>
    <name>Vehicle</name>

EDIT: I corrected it as the first comment says, but now I receive

Error: Schema validation failed:
El elemento 'traciClass' no es compatible en este contexto.
        SubType: Unspecified

        Rule:

The element traciClass is not compatible in this context.

Original post continues:

This is a template of how the different objects should be defined in XML for Java, but I am wondering whether this structure will vary for C#.

<?xml version="1.0" encoding="UTF-8"?>
<!-- This file is used to generate a Java class with the same name for a 
    TraCI object. This saves manually writing a lot of boilerplate code. -->
<traciClass>
    <!-- The name of the object. It will be used as the class name. First letter 
        is capital. Must be equal to this document's file name. -->
    <name>ExampleTraciObject</name>

    <!-- The javadoc of the class that will be generated. -->
    <javadoc>
    Put your object description here.
    </javadoc>

    <!-- Lists all the other repositories that are needed by the queries -->
    <repos>
        <repo>Repository1</repo>
        <repo>Repository2</repo>
    </repos>

    <command>it.polito.appeal.traci.protocol.Constants.CMD_GET_VEHICLE_VARIABLE</command>

    <!-- List of all "read" queries, i.e. those that don't change the state 
        of the object and return a value -->
    <readQueries>

        <readQuery>

            <!-- The name of the query. If the name is XXX, the Java class will contain 
                a method named queryXXX() -->
            <name>ReadSomeValueQuery</name>

            <!-- The enum name of the query. It will appear as an enum entry
            in the inner Variable enum, and can be used with the getReadQuery() method -->
            <enum>SOME_VALUE</enum>

            <!-- A numeric value or a constant of type int that tells the variable 
                ID -->
            <const>it.polito.appeal.traci.protocol.Constants.SOME_VARIABLE</const>

            <!-- The Java class name that can make the query. It must be a subclass 
                of ReadObjectVarQuery. If the class is on the package
                it.polito.appeal.traci, the package name can be omitted-->
            <query>ReadObjectVarQuery.IntegerQ</query>

            <!-- The return type of the query. It must be the same type (or a supertype) 
                of the type parameter V specified in the above class. 
                Leave it empty to use the query class as the return type. -->
            <returnType>java.lang.Integer</returnType>

            <!-- If true, it means that this value may change at every simulation 
                step. -->
            <dynamic>true</dynamic>
        </readQuery>

        <!-- add other read queries here -->
    </readQueries>

    <!-- List of all "change state" queries, i.e. those that change the state 
        of the object and don't return a value -->
    <changeStateQueries>

        <!-- The syntax of a changeStateQuery is similar to readQuery, differences 
            are listed below. -->
        <changeStateQuery>
            <name>DoSomething</name>
            <query>DoSomethingQuery</query>
            <!-- Lists the read queries that may be changed by the execution of this 
            query, identified by their name. Calling this query will clear the caches 
            of the queries contained here. -->
            <affects>
                <affect>ReadSomeValueQuery</affect>
            </affects>
        </changeStateQuery>

        <!-- add other change state queries here -->

    </changeStateQueries>

</traciClass>

Is it a problem of XML syntax?