Educating Rita (Act 1 Scene 5)

She emphasise how important the course is to her by saying that to take that course is a way to “find herself” inside.
To me, what she may want to say is that learning will help her to discover the abilities she is unaware of. That is, no one knows what is able to do until you try to do so; then you will know if you succeed or fail.
That decision of taking the course will enable her to feel more confident since she will “find herself” as she says.
She also emphasise the importance of going to the course by saying that coming there makes her stronger because she feels that she is learning a new world instead of wasting her time going to the pub with her husband and mates. I think that because of that she refuses to go to the pub with Frank when he invites her. She doesn’t want to keep doing those things that now she considers being unworthy for her new life.

Educating Rita (Act 1 Scene 3 & 4)

Rita’s essays (on Howards End and the two she writes on Peer Gynt) tend to be quite short since she does not give any reasons supporting what she writes: a sentence that is just the basis of an argument. What she needs is to think over more ideas so as to justify what she states in her essays.
She considers that coming there (to attend classes) makes her stronger because she feels that she is learning instead of wasting her time going to the pub with her husband and mates as she says.
Rita knows that education is very important to change her life in some way; she feels that she is learning something different everyday so that she feels more confident so that she says that coming there makes her stronger.