I have Purchased the creative cloud plan for Photographers...Can I Just save my Data only on my HD

You can also look at it this way…it depends on which Photography Plan apps you are using, and how you use them:

Lightroom Classic: Originals must be stored locally. You do not have to connect to cloud storage at all, but if you do, originals are never synced to the cloud, only Smart Preview proxies. If any originals are in cloud storage (because the mobile/web/cloud versions put them there), Lightroom Classic will download and organize them locally.

Lightroom, cloud mode: Originals must be stored in the cloud, local storage of originals is not possible except as a local copy of the original in the cloud.

Lightroom, local mode: Originals must be stored locally, but any cloud-backed features will not be available.

Photoshop: Originals can be stored as any mix of local Photoshop documents and Photoshop Cloud Documents. You can also choose to store everything locally (using no cloud storage) or all as Cloud Documents (using no local storage). Other cloud features, such as Creative Cloud Libraries, are optional.

Adobe Bridge: Browses local folders only, but can publish to some cloud services.

Adobe Camera Raw: Edits local images only. Might connect to the cloud if you apply an AI feature.

Mobile (phone/tablet) or web browser versions of any apps above that have one: Cloud storage only. Local files can only be selected for import and upload to the cloud.

All Creative Cloud apps must connect to the cloud for licensing checks and some background services such as Adobe Fonts.

In addition to the other answers, if you are using Lightroom Classic, you MUST (it is not optional) make backups of your work; this means you need a backup copy of your catalog file and backups of all of your original photos; said backups must be (it is not optional) saved on a different hard disk than the originals. Backing up the catalog file can be done using Lightroom Classic (look in Catalog Settings, General tab, under the heading "Backup"); backing photos must be done outside of Lightroom Classic.

Just making sure you understand completely. There are two versions of Lightroom. One called Lightroom Classic which only uses local storage and is typically referred to on the web as just Lightroom since it is really what everybody knows as Lightroom. Another version is called Lightroom Desktop which very confusingly uses the cloud as its main storage. It is basically a port of the Lightroom version for mobile (iOS and Android) platforms to desktop operating systems (hence the name). Adobe heavily markets the latter and hides the former which leads to no end of the confusion and many people end up installing the cloud based version while wanting the normal Classic version and we deal with that a lot on this forum. There is one bright point and that is that since the last version, Lightroom Desktop (i.e. the cloud based version) also has a local browser mode, which allows you to see and edit locally stored images. It does not allow you to do all kinds of things you might expect such as searching in your entire colletion and such so if you want local storage, I would strongly recommend you only use Lightroom Classic which is a much more comprehensive solution if you are working with locally stored images.

And to add to @JohanElzenga message: if you try Lightroom (without classic!) you will be limited by the 20Gb cloud space. With 40Mb raw files you will be easily reaching the limits.

You can't even use the cloud for that if you wanted to. Lightroom Classic does not use the cloud to save its data, nor does it save the images in the cloud.