From my observations working with startups (bootstrapped or funded), one of the biggest hurdles for new founders is getting out of the way and trusting other people.
It happens in marketing, product development, sales, and support. Founders often think they're the only ones who can possibly do it well enough, so they take on an increasing number of tasks until it starts to hamper their own growth.
Besides limiting your business' potential, doing everything yourself also makes it really hard to sell your business or even just take a week off.
Start small - pick a task that's so easy it's almost silly to delegate. Hiring someone else to do it will force you to learn how to define and evaluate tasks rather than just doing them all yourself.
Don't limit yourself to only hiring junior people - hire people who don't need as much hand-holding and then get out of their way.
Gradually up the difficulty/importance of tasks you delegate - I'm not saying you should outsource sales on day 1 here. I'm just saying that if writing code is limiting the amount of time you have to hop on sales calls, you might want to pick a lane.
Track your time - This is how I figure out which tasks are ready for a new hire. When I see myself spending 8+ hours/week on one task, I start to figure out how I can delegate it.
Document and automate - even before you hire. This is a good practice and it'll make it so much easier to slot other people into your workflow.
Simplify your business - many small companies try to do too much. Pick a profitable niche that gives you enough margin to pay other people and then drill down. Don't take on extra side projects just for the money; they're a distraction.
Do you struggle with delegation? Let me hear about it and how you're handling it!