Are you familiar with CSS? It’s not that easy to change the layout of a theme and that kind of change must be done in a Child Theme or using Custom CSS (add via a plugin if the theme does not have it) so that your changes are not lost when the theme is updated.
When you have that set up, post in each of the theme’s own forum:
http://wordpress.org/support/theme/misty-lake
http://wordpress.org/support/theme/magomra
Only thing I want to change some parameters in css but I don’t know where.. Maybe I have to increase site width and fix right sidebar?
If you modify theme files, your changes will be lost when the theme is updated. These are theme-specific questions – CSS is 100% theme-specific – please post on the themes’ own forums.