Acne and sensitive skin are really difficult to deal with depending on the type of acne it is. You need to find which type of acne you have and go from there. If you have acne scars, it is likely you have or had cystic acne. It means your skin likely has open wounds on your face and thus, you should treat it like such. There are three primary layers of skin: the epidermis, dermis, and hypodermis. Sometimes blackheads and acne penetrates to the dermal layer which is the middle layer. So you would need to use a soft cleanser that gently removes layers of oil, dirt, and buildup. You really don't need anything fancy so I highly recommend cetaphil or la rosche posay as a cleanser. You do need to find out which skin type you have. Oily, dry, or combination. This will also make a difference as to which type of facewash you choose but the two brands mentioned above have formulas for all skin types. Personally, I have dry skin but use to have oily skin when I was 10 to 16 years old. so remember that your skin type can change and its important to keep an eye out on that since some products can make your skin more oily or more dry.
When you are washing your face, you want to wash it with warm (not hot) water. And I highly recommend only washing your face once a day with soap - generally at night. In the mornings, you will likely be okay with just splashing your face with cold water since sometimes your pores open up overnight from warmth and the face tends to be "puffy" when you wake up. This helps take down this bit of swelling and closes the pores to keep them from "accepting" oils. The best way to think of your pores is as wells, sweat, dirt, oil, and pollen/irritants are more likely to enter those wells after you wake up. Which is why I prefer washing face with soap at night. One thing I discovered is that soap that makes bubbles will often hurt your skin more than help it because of a leftove residue which can cause acne. If this is something you are concerned about, definitely go with La Rosche Posay facewash since it doesnt get all bubbly. It also balances out your skin from my experience with it. But if you aren't concerned and want something that will be okay just in general, use cetaphil. Both are pretty cheap.
Ok now that soap is covered, youll want to find a good moisturizer and sunscreen since the sun and its rays can be so damaging and having a moisturizer regardless of your skindtype is vital. For an overall moisturizer no matter the skin type and daily use, i recommend Boscia Cactus Water Moisturizer. You literally can not go wrong with this product. I tried it a long time ago, it works perfect. It is cooling and gel like. I have never had any bad experiences with this product regardless of skin type. One of my best friends has cystic acne and she switched to that product and it actually cleared her skin entirely. It is also good at getting rid of acne scars and hyperpigmentation. it just takes a little bit of time. For the sunscreen, just find one that works with your skintype. Anything with an SPF of 15 or above is good. But you need to pay attention to where you are in the world and what the UV rays "look" like where you are. You may need more depending on that.
As for everything else, you'll really want to look ino buying a gentle toner and if you have the money to invest, i recommend buying a 'serum' thatworks best for your skin later on down the line. Also for small "spot" acne, there is a product called "on the spot" that you can use and that takes care of the spots in a day. Really the trick is to keep it simple and know that you should keep up the routine for at least a month before switching it since you won't really see results until about a month in. Sometimes your skin will get worse before it gets better and again, that takes time so typically a month or longer is how long you want to try a routine before dismissing it if you don't like it.
SO overall your routine will look something like this:
MORNING: cold water (after brushing teeth, residues left behind can cause problems), toner, on the spot (optional) serum (optional), moisturizer, sunscreen.
NIGHT: wash face with warm water, rinse with warm water, use cold water afterwards to close pores, pat dry with a clean towel, toner (optional at night), moisturizer (also optional).
Sometimes you can use a night skin treatment if you decide you want to invest in one. But if you do, id only use it 2-3 times a week or as directed. if you tend to get overheated at night, i wouldn't use a moisturizer at night just because the oils may get trapped. possibly. its kind of trial and error when it comes to that. but yea, just give it time and i wish you luck! if you have any questions, let me know. I have a lot of experience with it and have been through a ton of products.