Short answer: For starting a besana (eating/consuming) in the morning, the common Pachkhān to follow is the Navkārshi (Navkārsi) Pachkhān.

What to do:

• Wait about 48 minutes after sunrise.
• Sit quietly, fold your hands and recite Navkār three times.
• Then you may consume water (and later food) as per the Pachkhān rules you choose (for a simple morning besana, Navkārshi is the standard starting point).

Why this helps: Navkārshi Pachkhān is specifically meant for consuming food or water in the morning after a short wait post-sunrise, with the Navkār mantras recited first. It’s a widely followed starting point when one wishes to begin besana in the morning.

Other related options you may hear about (in case you plan a longer fast or stricter observance):

• Egāsanā / Biyāsana Pachkhān: two common morning options for how many meals you’ll take, also involves Navkār recitation. If you plan two meals after a delay, this is relevant. You may read more about these Pachkhān in community resources.
• Upavas / Tivihar Pachkhān and others: for more extended observances, specify start and rules with a Pachkhān chosen in the morning.

If you want, I can help you choose a specific Pachkhān based on whether you plan a single-mash (ekāsan) or two-meal (biyāsanā) morning, and whether you intend to drink water only or also eat.

You can read more here