There are many abilities and upgrades throughout Metroid Dread and you will need to acquire them if you hope to proceed. Samus’ primary weapon is her arm cannon and it can be upgraded in various ways. One of these is the Wide Beam.
The Wide Beam is found in Dairon which can be traveled from Cataris. When you first arrive in the zone, it will be without power and darkened. You must navigate its corridors to find the generator. Once you do, you can restore power. You will need to backtrack to get the Wide Beam.
Related: How to unlock the Phantom Cloak in Metroid Dread
You will need to backtrack to get the Wide Beam. Look for a missile door in the northeast. Through this door, you will find a Chozo Statue that is holding the Wide Beam upgrade. Break the orb to collect this upgrade.
The Wide Beam allows Samus to fire three blasts from her arm cannon instead of the single beam. This upgrade is handy for both combat and exploration. By default Samus will fire three blasts and if you hold the fire button, she will shoot a charged version. This can quickly take out enemies including those who are hurt by regular blasts and can move/open Wide Beam blocks and doors.
For more information on Metroid Dread, check out How to defeat Corpius in Metroid Dread and How to parry in Metroid Dread on Pro Game Guides.