Upgraded to Windows 10 - apps too small, and scrolling is up and down. How can I fix this?

[Windows Central Question]

upgraded to windows 10 - apps too small, and scrolling is up and down

how do i make the apps bigger in windows 10? they all got smaller with the 'upgrade' - also, how do i make scrolling through apps do side to side like it used to do, and not up and down