Can I zoom text size on the iPad in Safari?
You can double-tap to zoom in to a section. I find this feature very useful. As you use it you'll soon learn where to double-tap to get the zoomed-in view you want.

Safari does not have support for changing just the font size without zooming the page, but Opera Mini does have that feature. You can go to settings and choose from small, medium or large font sizes.

But note that this only works on some websites, not all. This is because changing font size can very likely break the website design/layout. Website creators like to control the user experience so they explicitly set the font size so the browsers can't change it.