Business start-up

Go for it!  I would strongly recommend making sure your pricing covers your helper as well and as a pro who has built (and sold) two service businesses, here's my quick list for making the shift

1. Implement simple systems EARLY: Invoicing, tracking my numbers, asking for REVIEWS and collecting email addresses are four I'd start with out of the gate.
2. Set up dedicated business bank account:  NO COMINGLING FUNDS.  Keep your business and your personal separated! You'll thank me for this one. Small town banks are great for businesses starting out.  Whether you're a sole proprietorship or you go big and open an LLC from the jump, it's so important to keep those $$$ each in it's own account so things don't get squirrelly for tax time.
3. Master your numbers from Day 1: what do I mean by this one?  Clients I've worked with wish they had understood that "revenue alone doesn’t tell you if you’re profitable". Knowing the direct costs of each job (like fuel, specific materials, labor for that job) is fundamental to accurate pricing and understanding your true profit margins.  
4. Prioritize strategic time (even when you're small):  Set aside time each week to look strategically at your business. Think of it as a CEO time - an appointment you keep with yourself each week to look at what your business did, how many leads you got, how many reviews you snagged, what did you bill/receive in income, how many quotes did you send out, goal-setting for next week and reviewing last week's goals. This may start as a monthly appointment with yourself but consistency will pay off and help you scale so much faster!