What type of wall texture is this, and how do you remove it?
That looks like skip trowel. Regardless, your solution depends on if it's plaster or drywall mud.

If it's plaster, you can skim coat it or have it removed and reapplied. Both require a bit of skill and it's best done by a professional. This will not come cheap. 

If it's just mud, a skim coat is fairly easy to do but takes time and patience. You can thin down some ready mix mud, apply it with a 3/4 nap roller, then scrape off the excess with a 12" drywall knife. This will probably take a few coats, but it can be accomplished by a diyer. After you have the wall to mostly smooth plane, prime with PVA and you can apply your orange peel texture. Then just prime and paint. 

Another solution is to put on 1/4" drywall directly over it. But this is a big job with taping seams, altering trim around doors and windows, extending electrical boxes, and applying texture. 

Just to cover all options, it's "possible" to sand smooth. Even renting a power sander hooked up to a shop vac, this will produce a lot of dust. Plaster and certain drywall mud types are really hard to sand. I wouldn't do it. 

Also, I would rent a texture sprayer. The cans of texture are really only for touch up and the fumes are pretty bad. Mask off with builders paper or poly sheets anything you don't want texture on. It's all in the prep work.