Can I have some creatures attack the planeswalker and other creatures attack the player?
Yes, after you choose which creatures are attacking, you may choose whether they are attacking the defending player or a planeswalker that player controls.
From the comprehensive rules:
508.1. First, the active player declares attackers. This turn-based action doesn't use the stack. To declare attackers, the active player follows the steps below, in order. If at any point during the declaration of attackers, the active player is unable to comply with any of the steps listed below, the declaration is illegal; the game returns to the moment before the declaration (see rule 717, "Handling Illegal Actions").
508.1a The active player chooses which creatures that he or she controls, if any, will attack. The chosen creatures must be untapped, and each one must either have haste or have been controlled by the active player continuously since the turn began.
508.1b If the defending player controls any planeswalkers, or the game allows the active player to attack multiple other players, the active player announces which player or planeswalker each of the chosen creatures is attacking.