The foot pictured is the general purpose presser foot from my Singer 15-91 and in some books is called the hinged presser foot. It also fits the 201 and many other Singers as well. If you're not used to a straight stitch sewing machine the foot might look small and skinny to you--like you're sewing with a zipper foot.
This is because it fits the narrower feed dogs of a straight stitch machine. You can see these in the next photo. If you have a zigzag machine your basic pressser foot will be wider for the wider feed dogs and to accommodate the back and forth movement of the needle when zigzagging.
If you have long curves to sew, angle it.
lower the presser foot and sew as you normally would. The next photo shows the end result with the reinforced stitches at the beginning. At the end you would reverse the fabric and make another few stitches.
Here is a quick easy seam my mother used to use on some play dresses for me when I was little. Sew your seam as usual and then sew again about an 1/8 of an inch away in the seam allowance. My dresses were made of firmly woven cotton. You've seen cotton edges after they've been washed a few times probably--they fray, then fuzz up and don't ravel. These dresses lasted through me, my sister, and her daughter and are packed away for whoever else will want them. They are more in danger of the fabric wearing out than the seams giving way.
So, yes, you're clothes sewn on a straight stitch sewing machine will last.
As if this post wasn't long enough here is a practice lesson from my Singer reference book of all the things you should know now:
1. You should know how to oil your machine.
2. Remove and replace face plate (if it's a removable one) and throat plate.
3. Remove and reset needle.
4. Wind bobbin.
5. Thread machine.
6. Stitch a plain seam making sure you follow the basic steps (take-up lever at highest point, etc.)
7. Know how to stay seams at each end.
8. Understand tension. Change the upper one and see the results if you like. Make sure and put it back to normal when you're done.
9. Get some scraps of different fabrics (corduroy, wool, cotton, chiffon) and practice sewing on them.
10. Try out some different seams.
Next week I'll start showing some of the fun attachments that came with a vintage sewing machine. If you don't have any, they're all still available--even new. Plus, they're for all sewing machines, not just straight stitch.