Welcome! Not really the place you want to be but many have found it very helpful. The first few days/weeks are very confusing - whole new language, procedures you know next to nothing about, and people automatically get scared about chemo. It's a lot to take in. Most find it easier once they have started, you have something more specific to concentrate on.
Others on on this site will
kindly direct you to lots of resources and useful information. Try not to get too alarmed about chemo - reactions vary a lot, and there is virtually no way to prepare yourself until you start so best to try not to overthink it. Once you start, you will get an idea of what each treatment will be like, a cycle, which will help you to work around good days and bad days. Some people like me were pretty lucky and didn't really have bad days (no nausea or fatigue) but many get a bit of both.
The main aim is to treat you quickly and effectively. Ask questions, from your medical team or here, don't waste your energy worrying about things that may be easily answered. I hope you have family or friends to support you, it can take them a bit of time to get used to the new situation too! Deep breaths, you can do this, best wishes.