It is very common for beginners and even advanced beginners to not be able to formulate a plan. It never entirely goes away, but eventually becomes rare.
It is very difficult to learn chess from books alone. You really need someone better than you to point out what your doing wrong. We could help you with a few things just from this sequence alone, but you have to understand that if you've only played a bit in school, a few casual tidbits from veterans won't really take you all that far.
Find an adult chess club in your area and see if it meets at a convenient time. They usually have players at all strengths. Its true that you might be the weakest member for a time, but its unlikely anyone would think twice about it; people do start at all ages. If you have the cash, lessons are another choice. Or just have fun, dont worry about it, and maybe learn to write down your moves and post a full loss here now and then for help.
Hi!, I'm not very good at chess "anymore" (I used to play in school YEARS ago and between my schoolmates I was pretty "medium-good", but I never continued to play and now I'm totally lost in "what should I do now..."
This is an scenario that it keeps repeating to me (playing white):