How can i do that in Musescore?

attach your score here, if you want, and specify what you want to achieve. The clef is selectable from its palette (!?!)

It's normal / correct to repeat the clef in these situations, but if you wish to make it invisible, you can click it and press "V".

For the barlines: check the attached (if it works)

As far as I know, that's also non-standard notation - what MuseScore does by default is according to standard emusic engraving practice. But if you have some special reason to need to deviate this, you can add the double bar from the Symbols palette (press "Z" to display). Or, if you have enabled the option to display barliens at the beginning of each system (which is the only situation I could imagine wanting to see one here after the break as well), just click the barline that appears at the beginning of the measure and then apply the double bar normally from the palette (double click the icon).