In the U.S., it’s fairly easy too if you use quickbooks or similar, but the IRS is much harder to deal with than HMRC, and is much more of a punitive organisation.
However, having an accountant to talk to can give reassurance that you’re not going about things extremely stupidly.
The moment you start doing business in multiple jurisdictions (in the U.S., this includes multiple states), it starts to get a lot more complicated and using a professional makes sense. International tax is a huge pain, especially where the U.S. is involved.
I do think the general idea that it’s much better to try and run a straightforward business without complicated tax structures when you’re young really rings true. It’s better to focus on generating revenue than trying to squeeze out every penny of tax optimisation.