Assuming you're in the USA, technically, you don't have to form an LLC at all. Since you'll be a sole proprietorship with no employees, you can use your own SSN as your tax ID. Simply file a Schedule C with your personal tax return to report income/expenses.
If it's preferable in your situation to form an LLC for whatever reason, you can form a single LLC to cover all your business activities. Companies go into new lines of business all the time without getting a new tax ID for each one. The IRS doesn't care so much what
your business does, as they care that the business pays the appropriate taxes.
Of course, there's nothing stopping you from forming a separate business entity to handle each line of business, if that works better for you.
Which leads directly to the bottom line:
recommend you consult with a tax adviser, and possibly an attorney as well, before you make your decision. What you choose to do can have significant tax implications and you need to talk with an expert who's familiar with your specific circumstances. Casual advice from denizens of a free online discussion forum, no matter how experienced and well-meaning they may be, absolutely cannot
substitute for a real, professional consultation with an expert.