Do you want to work in a single line of music? You can do this if you have Page Layout View switched off. When you switch it back on you will return to the start of the line of music.

Using the automatic wrap around feature you can then either click 'Optimum' or specify the number of bars you want per line of music. Or you can chop it up manually, if you prefer.

The tenor clef in SATB scores and how to use Score Templates  

If you produce four part vocal scores you will need the octave treble clef for your tenors. To get it you have to go into the Score Template and look under 'Additional Clefs' (the so called 'common clefs' in this the top of this window do not include this, the tenor clef listed there is a C clef).

Until we can have the octave tenor clef more accessible the quick way to start a score containing the octave treble clef is to use a Score Template.

To open a score template go to FILE | NEW and select 'From Template'. You will see your capella files. When you open an appropriate score you will see a single stave - this is intentional! To insert the staves press CTRL+ENTER. If you prefer using the mouse click on INSERT | STAVE. In the window which comes up you can click on the 'Select all staves' button or tick the staves that you need at this point.

If you need more staves in your new score, press the System Template button and expand the template.