If you have not got a YouTube account it is easy to create one.
Go to youtube.co.uk and click the Create Account link
Fill in the form, they ask for your age because you should be thirteen before they allow you to upload.
If you already have a already got a Google account you add YouTube to it
Once the account is created you can upload your movie, click the upload link
If you have transfered your movie from your phone to your computer click the upoad button, you may be able to upload directly from your phone, depending which model you have –