I’m 33 and I have been doing minor repairs since I can remember. Sewing buttons on or holes shut. Or making tiny clothes for barbies, looked awful, but worked. There are special ways of hand stitches for different purposes, but in most cases it’s a trial and error approach that in 90% of cases won’t end in “error”. You’ll figure out what feels better (like one yarn or double yarn) very fast.

But only at age 32 I invested in a cheap seam ripper. It always seemed excessive since you can basically just use sharp little scissors for that. I was wrong. I fucking love my seam ripper and I use it as a scissor now. This is so satisfying I would never ever let anyone rip any seam open for me. That’s the orgasm of sewing.

Also, you might want to use a threading aid. Some thread is just a bitch.

Little side note: when choosing a thread to repair, try to go muted. If you have a green piece of clothing and a light green, dark green, and grey thread, very likely the grey thread will be the least noticeable, unless the green is the same shade. If in doubt go darker. For white thread I recommend going off white - unless you have a lot of white clothes, most of white stuff is off white (i.e. not crisp paper white). Some people say 100% cotton thread breaks easier than blend or polyester. So far I haven’t had any bad experience with cotton threats though.