I do not see preset patterns.

You can use tutorials to learn pattern mode. The MODX firmware announce page instructs you to use the Montage tutorials for now:

https://yamahasynth.com/modx-category/montage-os-v3-0-article-roundup

See "Pattern Sequencer Articles" section.

Welcome to YamahaSynth!

does OS 2 comes with any preset patterns?

No, it doesn’t — but many of the new Preset Performances were done by various programmers and Yamaha Synth artists. Many of them made Patterns which were turned into the Audition Phrases that accompany each Performance.

For example, if you recall the new Performance: “Out West” and run the [AUDITION], you’ll see the [SCENE] buttons outlining how each musical Section was composed.
Press [CATEGORY]
In the box with the magnifying glass, type: Out West
Tap the title to recall it.. press [HOME]

At least you can get an idea of how the composition was put together, Scene-by-Scene... The data was recorded to the eight Scenes, then using the Pattern “Chain” function, it was laid out as a linear structure and converted (notice it was shortened for the Audition Phrase, (Scene 5 was the Bridge in the original data).

I think they decided rather than write data into the user memory of Sequencer, they would simply install the examples as Audition Phrases.
You can observe it is constructed from several four and eight measure SCENEs... as it plays the Audition you can observe the Scene lights still indicating what was recalled for each musical section. Each Scene is a musical section, each Scene memorizes the synth and mixer settings for that musical section. This is so you can, on a per musical section basis, change things relating to which sounds are being triggered, which sounds are being effected, which sounds are under control of the Super Knob, etc., etc.

also how I delete unwanted patterns that I have recorded ( not 1 particular track but the whole pattern

From the Pattern screen:
Tap “Edit/Job” > “Track” > “Clear” > set the Track = All > set the Scene = All > tap the box in the lower right corner to execute.

Alternate Method: Every MIDI (Song) and Pattern that you record is automatically stored in the “Song” or “Pattern” Folder.
Press [UTILITY] > “Contents” > “Data Utility” > here you will see the various internal memory Folders, tap the Pattern Folder to see a listing of your current Pattern data > touch the title you wish to work with... a pop-in appears to Rename or Delete the item.

Thank you Jason and Bad Mister for excellent and relevent info, would love Bad Mister to do a video exploring pattern sequencer 😀