Inserting double bar and repeat signs

1. Drag the barline to the measure before except a start repeat that's dragged to the measure after.

2. ctrl+K lets you enter chords. It's quite smart but you will want to read for specific things to type for various chord symbols (if you use the jazz font it supports the delta symbol!)

3. Add swing text from the swing palette or turn on swing in the menu Format->Style->Score

Soee

1. https://musescore.org/en/handbook/barlines
2. https://musescore.org/en/handbook/chord-symbols
3. https://musescore.org/en/handbook/swing

In general, please do yourself the favor and read the handbook front to back, at least once, it is time well invested