WAY OVER SUGAR AND SALT INTAKE

To avoid sodium, you pretty much have to avoid most packaged foods. To avoid sugar, you have to avoid most processed baked goods and sweets.

Fresh fruits/veggies
Meats that you don't salt
Label reading for everything else

That said, unless you have medical conditions where overages of these cause problems, you really don't have to worry about them.

Yeah take a look at the back label anyway
It may say low sodium but in reality its still packed full.

Best thing you can do is eat as fresh as possible!
As mentioned anything canned or processed is going to be loaded.

For salt, like others said, minimize your intake of processed foods. Some foods are harder to avoid unless you have a lot of time to make it yourself (like pasta), but other things like cooking dried beans take a little planning but little work to actually make. Even "low sodium" processed foods still have a lot of sodium in it to cover up all sorts of terrible flavors that would exist in preserved/precooked food.

For sugar, again minimize processed foods. However, I do want to note that my fitness pal does not differentiate between intake of natural sugars (like lactose in milk and fructose in fruit) from added sugars. What really matters at the end of the day is how much added sugar you're consuming. I eat a lot of fruit usually so I changed my nutrient that it tracks from sugar to fiber because I was tired of it telling me I went over. On a typical day I would have less than 10 grams of added sugar, which is below what is recommended for women.