I have a visual force page with two buttons in my Opportunity Page Layout. The buttons are linked to a controller that runs a multipage wizard.

When clicking the button, it should open a new tab with Page 1 of the wizard, but instead it opens in on the opportunity page itself which I don't want.

here is the page:
 

<apex:page standardController="Opportunity" Extensions="create504Controller" tabStyle="Opportunity" sidebar="false"
 lightningStylesheets="true">
  
  <!-- make sure to add syling attributes to the text on this page -->
  
  <h2><Strong>To Create a 504 2nd Trust Deed, Click Here</Strong></h2><br/>
  <apex:form >
      <apex:commandButton action="{!step1}" value="Create 504 2nd TD"/>
      <apex:commandButton action="{!save}" value="Edit 504 2nd TD Details"/>
  </apex:form>
  
  
</apex:page>

Here is the top part of the controller. 

public class create504Controller {

    Opportunity TD1st;
    Opportunity TD2nd;
    String OppId;
    
    public create504Controller(ApexPages.StandardController controller) {
		OppId = controller.getId();
        
        this.TD1st = Database.query(getQueryStatement(1));
    }

    public Opportunity getTD1st(){
        if(TD1st == NULL) TD1st = new Opportunity();
        
        this.TD2nd = Database.query(getQueryStatement(2));
        
        return this.TD1st;
    }
    
    public Opportunity getTD2nd(){
        if(TD2nd == NULL) TD2nd = new Opportunity();
        return this.TD2nd;
    }
    
    public PageReference step1(){
        ApexPages.StandardController sc = new ApexPages.StandardController(this.TD1st);
        return Page.create504pg1;
    }
    
    public PageReference step2(){
        return Page.create504pg2;
    }
    
    public PageReference Finish(){
        
        insert TD2nd;
        update TD1st;
        
        PageReference originalOpp = new PageReference('lightning/r/Opportunity/' + this.TD1st.Id + '/view');
        Return originalOpp;
    }
    
    public PageReference Cancel(){
        
        PageReference originalOpp = new PageReference('lightning/r/Opportunity/' + this.TD1st.Id + '/view');
        Return originalOpp;
    }
    
    public PageReference Edit5042nd(){
        
        PageReference OppTD2nd = new PageReference('lightning/r/Opportunity/' + this.TD2nd.Id + '/view');
        Return OppTD2nd;
    }
    
    
    public static String getQueryStatement(Integer option){
        
        String selectStatement = 'SELECT name, AccountId, Amount'
            		  +'FROM Opportunity ';
       
		
        String whereStatement1st = ' WHERE Id =: OppId LIMIT 1 ';
        String whereStatement2nd = ' WHERE X504_Related_Opportunity__c =: OppId LIMIT 1 ';
        String queryStatement;
        
        If(option == 1){ 
            queryStatement = (selectStatement + whereStatement1st);
        } else if (option == 2){ 
            queryStatement = (selectStatement + whereStatement2nd);
                               }
        System.debug('statement '+queryStatement);
        return queryStatement;
		        
    }
}

What am I doing wrong?