Can my teammate or coach give me advice during a match?

Only between games. World Squash Singles Rules (Appendix 6) define coaching as any communication, advice or instruction given to a player by any means, and permit it during matches only in the intervals between games (up to 2 minutes each).

Receiving coaching during play is listed as unacceptable conduct under Rule 14, so the referee can penalise you with a Conduct Warning, Stroke, Game or Match.

Player analysis technology (for example a sensor in your racket) may record or store information during a match, but you can't retrieve it during the match.