I have a yahoo and a google (Gmail) account I always have used the yahoo account but don't remember the gmail account password. If the two accounts are linked, will I delete both if i delete one of them? Where could I locate the place where I could change/create the gmail account? It might be useful to have 2 email addresses
Sincerest of thanks for any guidance you could offer...
Stan
Deleting one account won't affect the other one(s).

On Android 4.x you can head to Settings (the gray gear icon app), then scroll down to Accounts and tap + Add account. You'll then be able to select which type of account you want to add (some of the possible options are Corporate, Email, Exchange and Google). If e.g. you want to add a new Gmail, select Google account and proceed. You'll be required to inform if you wish to add a New Google account or set up an Existing one. Tap New and proceed.

Once you've added your new Google account, you can e.g. access the People app (the one that gives access to all your contacts), then tap the button having 3 vertically aligned dots on the lower right corner:



...so you can tap Accounts to select your accounts and what you want to sync on each one (e.g. sync contacts). There will also be a Contacts to display option, which gives you the option to choose which contacts (from which accounts) you want displayed by the People app.