If you are new to Salesforce, then I would strongly recommend that you create your own Free Salesforce Developer Environment. This will allow you to both learn and experiment with all aspects of Salesforce, and take the tutorials that are described on this website.
Even if you are working for an Organisation that already uses Salesforce and provides you with a Development Sandbox, you may still find that some features are restricted, and will require assistance from your Salesforce Administrator.
Our first article on working with Salesforce is Salesforce Data Migration. Even if you are not working on a Data Migration per se, you will still find these techniques useful for whatever your Salesforce project is.
As with any project, you should familiarise yourself with all of the technology involved.
You will find that this helps you greatly, when you need to understand and challenge some of the requirements that you are provided with. Your requirements will not always be perfectly described and you will need the knowledge to be able to question these before you have spent a significant amount of time coding something that just doesn’t work.