Lock out of my laptop

Hi my name is Vanermi.

I have a Dell Inspiron 15 3000 seires Windows 10 laptop. Recently I been having trouble with the task bar and the home and shop icons.For example on the home icon and button the home tab doesn't appear even when I wait a full minute. Or when I want to change the power seting on the battery it doesn't appear either or the volume. Yet my Dropbox icon worked just fine.

So I decided to do as a person suggested and try to "restard" it. So when I restard the whole laptop and enter the login screen, it change the login metod to the windows account password when I originally had the pin number option.

So with no worry I just type my email password and it said it's wrong. I try it a few more time with the same result. So I think it just that I have to change the password so I do (having to wait a whole day). When I try to login again this time with the new password it still says that the password is incorret.

So I think "oh maybe it because the laptop hasn't connected to the internet so it haven't had the change to update or sync". So I go to where the wifi logo on the login screen is and see that instead of the wifi icon there's a square with an red X. So I click on it to see if my wifi networck appears, it does and I try to connect. Yet even do the laptop IS connected to the wifi the red X still appears on the square.

ANd during all this the laptop still wont let me long in with the new password!! TT - TT

So my question are:

How can I ix this problem with the pass word?

How can I get in with having to resorte to the factory reset? (BECAUSE THERE'S NO WAY I WILL LOOSE ALL OF THE THING I HAVE IN IT!)

And

What's wrong with the wifi? And How can I fix it?

Please help!