Non-destructive approaches
I strongly encourage non-destructive editing where possible. Check out https://resources.waverleycameraclub.org/non-destructive-editing/ for some of the reasons why. Rather than changing your original image, try to do the edits on separate layers over the top of the original. That way you can always go back and refine your edits if you want to. Once you change the original, it is very hard to undo.
Lightroom – spot healing/healing brush tool
This is a powerful tool. You can set the brush size and feathering. Choose either Clone mode or Heal mode. Then spot or paint over the area you want to repair. LR will (non destructively) find an area and use this as a source to repair the area you clicked/brushed. LR shows the source area as an outline. If LR chooses the wrong area, drag the source area to a more appropriate region. In Clone mode, the repair will duplicate the source area and in Heal mode LR will interpolate textures and blend. If the repair with one mode doesn’t look quite right, try clicking on the other mode to see the effect.
Read more at https://helpx.adobe.com/lightroom-classic/help/enhanced-spot-removal.html or search the web for more detailed information.
Clone stamp
The clone stamp tool is very powerful. In photoshop the tool has many options. It is well worth while exploring each one and finding out what they do and when to use them.
I recommend creating a new layer over the layer you are repairing. Set the clone stamp tool to sample “Current and Below” and make your edits. The cloned areas will appear on the new layer overlying the source layer. If you make a mistake you can erase it from this layer without affecting the original.
You can find more about Clone Stamp tools in Adobe’s learning resources (eg https://helpx.adobe.com/au/photoshop/user-guide.html) or search the web.
Spot/Patch healing brush & Content aware fill tools
These powerful tools (best used on a new repair layer over your original source layer) have a plethora of options. Rather than re-inventing the wheel, here is a link to these tools on Adobe’s web site. https://helpx.adobe.com/au/photoshop/using/retouching-repairing-images.html