I'm a new user of Inkscape on Mac OS. I know a bit of Illustrator but I find it too heavy so I wanted to shift to something more...friendly. That's why I have tested Inkscape. It seems to work perfectly and fits with my need.
however I have few little issues I would like to fix.
1) I don't know why but I choose a font (I need Helvetica) and click Apply...nothing happens. The font "sans" (I assume it is "without" in english

2) for resizing....I don't at all how it works. Let's say I draw a rectangle and I change one dimension, automatically the others change also, including the stroke for the border. Is there a setting avoiding this?
I understand that those questions could appear simple, but it will really helpful for me if you could give some advices to fix my problems.

Since I'm French, I apologize in advance for my English.

Thanks a lot for your help.