Here is a short list of music terms you should know in order to play music well.
Accent – play this note louder than the others. Abbreviated > over or beneath a note.
Allargando – slower, louder and in a broad style.
Crescendo – gradually get louder
Decrescendo or Diminuendo – gradually get softer.
Forte – loud. Abbreviated f.
Fortissimo – very loud. Abbreviated ff.
Legato – Smooth and Connected. Instead of tonguing notes ‘ta-ta-ta-ta’ (hard tonguing), legato notes are best played ‘ta-da-da-da’.
Marcato – short, accented, loud. Abbreviated ^ over a note or under a note (flipped upside down under a note).
Mezzo Forte – medium loud. Abbreviated mf.
Mezzo Piano – medium soft. Abbreviated mp.
Piano – soft. Abbreviated p.
Pianissimo – very soft. Abbreviated pp.
Tenuto – play notes full value/full length of time. Abbreviated by writing a straight line below or above a note head.