Here are my recommendations, with my rationale for each. Hope this will be helpful not just to you but to others as well.
First, make certain that what you're buying is indeed *Heavy* Whipping Cream. If in doubt, check the calories. There is also a product sold as "Whipping Cream" and they are, of course, completely different. You want to make sure you're getting the good (fat) stuff. There have been others on here that accidentally bought the wrong product, and then wondered why they didn't get the results they expected. If dosed effectively and consistently, the heavy cream will work. When in doubt (which when just starting out, you should be always in doubt), always check the calorie count to make sure you're getting the right stuff.
Second, if available in your area, try to find slightly larger containers. Personally I went with the 1 liter (32oz) size because it was the most economical and was straightforward to portion into 4 servings. Plus, each liter corresponds to just under 1lb of fat in terms of calories, making it quite straightforward to estimate the expected gain.
Third, though it is tempting, don't take in more than around 240ml (1 cup) at a time. 240ml of heavy cream contains about 820 calories almost entirely from fat, which is quickly approaching the maximum amount your body will be able to effectively absorb (about 100-120g of fat in a sitting). Some can take more than that in at a time without apparent digestive issues, but it doesn't mean they are getting everything they should out of it. Just because you don't have heartburn, gas, etc, doesn't mean your body is doing a good job of using what you drink.
My recommendation is to drink 240ml in the morning and 240ml in the evening, approximately 12 hours apart. Sure, you could chug half a liter in a single sitting, but your body simply is not going to absorb that in the same way and your chance of digestive discomfort goes up.
Now, let's say you follow the 2x240ml recommendation each day. How many pounds per week can you expect? Well, based on the calorie count while correcting for some minor metabolic losses, that comes out to about 3.2lb of fat per week. If you do this for 3 weeks, you'll be sitting just under 10lb. Do it for another week, you'll get another 3lbs. You probably don't want to move much faster than that pace anyway, just in the name of not getting stretchmarks everywhere, lol.
It was my experience that once I had exited the heavy cream cycle and let my body stabilize for a few days, the gains from heavy cream settled out very closely to what I expected. Everyone has a slightly different experience though, and I think dairy-fat nature of heavy cream means that your existing visceral fat stores play a role in how the gain goes as well.
Best of luck.
2 years