Hallo @candela, and welcome to the Dorico Forum!
For the Chords Symbols, you can change the appearance in Engraving Options: menu Library/Engraving Options/Chord Symbols
For the noteheads, here an answer by @dspreadbury from another similar post:
Hallo @candela, and welcome to the Dorico Forum!
For the Chords Symbols, you can change the appearance in Engraving Options: menu Library/Engraving Options/Chord Symbols
For the noteheads, here an answer by @dspreadbury from another similar post: