There are texture paint available for the homeowner that can be purchased through paint stores and home centers. The product is usually white and could be tinted to a light color. There are also products available by Bondex that can be added to create texture in paint. You can also consider Venetian Plaster, which is a faux finish product that can add texture to a wall. It requires a base coat color and then use the Venetian Plaster over the base coat.

An 'orange peel' or 'splatter drag' could be sprayed onto the existing wall to hide the dings and etc. But unless they are really bad it might be better to just patch and fix as needed.....

I just retexturized my kitchen walls with plaster, the kind you buy in a 5 gallon bucket. I put on 3 coats, sanding between coats. Kind of like an old plaster wall. Then I primed and painted. Looks like old plaster walls from Italy or somewhere.

I've always used drywall compound/ joint mud for texture over (flat latex) painted walls. Works just fine in that situ and I've never had a problem with the it, even in bathrooms & kitchens. Might not if you're going over oil-based/ glossy surface though without priming first.

I primed my walls with oil base to seal in old paint and wall paper glue. Then I textured with texture paint. That was a big mess. Maybe there is a better way of putting it on than the roller they gave me to use but I ended up trowling it on like plaster but it was kinda runny for that. Then I painted with latex. Looks nice but that texture paint with its special roller was a disaster.