- Getting easily distracted is normal. Don't set a goal of never getting distracted: it's unrealistic and counterproductive. I've spent hundreds of hours meditating, and still get distracted (albeit more briefly). Instead, feel good when you notice you're distracted. The goal is to train yourself to notice and return to the sensation sooner, with positive feedback.
- Don't try to block out everything except what you're meditating on. That should be your main focus, but you should let yourself be aware of other things in the background.
The Mind Illuminated has some good practical advice in the early chapters. I can't vouch for the later chapters.