do you know any good US proxy providers? something on a cheaper side?Both work, doesn't matter which one you choose. If you're using a proxy make sure to remove the sim from the phone. Don't forget to put your language and region to the country you want to target.
Warm up is not needed. You can post immediately as shadowbans are random when you upload directly from the gallery. TikTok knows where and who to put out your content.