"any advice for new beginners."

Spend hours/days/weeks studying Seller U BEFORE you even try to list anything.

https://sell.amazon.com/learn

Read the Forum DAILY for an hour to see all the creative ways sellers (both new and experienced) find to get suspended.

Have an LOA in hand BEFORE you list anything.

SOURCE PROPERLY!

More and more frequently Amazon is taking a TWO STEP approach and if you are caught not doing both of the steps (or either one!) you will be suspended eventually.

DO NOT confuse AMAZON allowing you to list (or at least "ungate") an item or category and actually being APPROVED to sell a product. Amazon might ungate you for a CATEGORY, but there can be 100's of brands in the category and they ALL have their own restrictions.

AMAZON is only interested in FEES. They will allow a chimpanzee to list if it means they collect $$$$$.

Additionally, brands that you COULD sell yesterday may be restricted today or next week. Amazon is a moving target to deal with.

DO YOU have an LOA from the brand allowing you to sell on here?

If you have an LOA that specifically says you can sell on Amazon you MIGHT survive listing items.

More and more brands are providing a "whitelist" of their approved sellers and if YOU are NOT on the list you will be stopped in your tracks and probably hit with an IP violation.

DID YOU source from AUTHORIZED wholesale sources that your rep at the brand says are OK? You DO have a sales rep at the brand, don't you?

NOTE the verification is required from the brand that the source is legitimate and authorized, NOT from one of those touted on TikTok and YouTube as having "thousands of brands and products" that assures you that they are authorized.

If you have watched any YouTube or TikTok videos FORGET everything you saw there.