Paul is basically saying, "Hey, you tangible/visual learners, watch me then do as I do, and you'll stay in God's peace." Solid advice if you have strong mature, Christian mentors to look to.
Honestly, it's easy to find strong Christian mentors - if you want to. Commit to attend a mature church and engage with people in small groups, ministries, etc. If a mentor in your immediate circle is difficult to pindown, read books, or listen to pastors' podcasts. Mentors don't have to be people in your close proximity. (I love Priscilla Shirer, Life.Church, Passion City Church). Regardless of your access to mentors, if your heart isn't right - you aren't gonna get anything out of it.
Paul used words like "learned," "received," "heard and seen" which all speaks to a past active engagement. I can't learn if I'm not listening, nor pursuing. I can't receive if I'm not open, following, with hands and hearts extended. If I'm not willing to be committed to invest time, space, and availability, I won't learn.
Make it personal
Do you have a mentor? If not, do you want one? Why or why not?
What is struggle would you like to address with a mentor? Is there something hindering that?