I am really new to Apex and would like some direction in testing a class. Could somebody give me some pointers? I have read through the documentation and am having a mental block. The class is below.

public class StageStations {

    Integer numberOfAssets;
    Account myaccount {get; private set;}
    Asset myasset;
    Decimal hsid;
    
    
    public StageStations(){ 
        myaccount = [select id, name, Contracted_Stations__c from Account 
        where id = :ApexPages.currentPage().getParameters().get('id')];
        for( Asset a : [Select Station_ID__c from Asset Where AccountID = :ApexPages.currentPage().getParameters().get('id')]) hsid = ( hsid > a.Station_ID__c ? hsid : a.Station_ID__c);
    }
    
    public Integer getNumberOfAssets(){
     Integer noa = [Select Count() from Asset Where AccountID = :ApexPages.currentPage().getParameters().get('id')];
     return noa;
    }
    
    public Account getAccount() {
        return myaccount;
    } 
    
    public Asset getAsset() {
        if(myasset == null) myasset = new asset();
        myasset.Station_ID__c = hsid+1;
        return myasset;
    }    

    public PageReference cancel() {
        pageReference accountpage = new ApexPages.StandardController(myaccount).view();
        accountpage.setRedirect(true);
        return accountpage; 
    }


    public PageReference save() {
        myasset.AccountID = myaccount.id;
        myasset.Name = 'PES Station '+myasset.Station_ID__c;
        insert myasset;
        
        if (myaccount.Contracted_stations__c==[Select Count() from Asset Where AccountID = :ApexPages.currentPage().getParameters().get('id')]){
             PageReference acctPage = new ApexPages.StandardController(myaccount).view();
             acctPage.setRedirect(true);
             return acctPage;
        } else { 
             PageReference newAssetPage = new PageReference(ApexPages.currentPage().getURL());
             newAssetPage.setRedirect(true);
             return newAssetPage;
        }
    }

}