Hello Moe, ( hey, that rhymes. Might be a song in there somewhere :) )
Welcome to you.
Good to hear you are doing well and have some goals to aim for.
I agree that Lisa is very good at introducing and teaching the guitar. You will find, as you progress, that all the teachers on Guitar Tricks are also very good. That is why this site is so popular.
It can be a bit hard on the fingers at first. A common mistake is to press down too hard on the strings.[u] If the guitar is properly set up[/u] you will be surprised how little pressure is required to produce a nice clean sound. Try playing a note then gently ease off on the pressure to find out what pressure is required to produce the note.
It is perfectly OK to strum with your thumb. Later you may find a pick more usefull to produce a note or you might like to learn some finger picking techniques. It is entirely your choice. There are some excellent lessons on finger picking to be found on this site. There are no hard and fast rules about how to strum a guitar just common conventions.Do what you are most comfortable with.
I wish you well on your journey of discovery. Take it slow and easy and enjoy the journey.
Take time out now and then to let us know how you are getting on or if you have any questions.