Congratulations on losing 25 lbs
If you are new to weight training, I would suggest a full body workout for about 6 weeks or so ( 2-3 times a week). This will enable you to familiarize yourself with the various exercises and let your body adapt accordingly. You also need this time for your tendons and ligaments to adapt. I would use moderate weights until you feel comfortable with the movements.
Stick with the compoung movements such as squats, bench press, followed with the isolation movements like barbell/dumbell curls ...etc
You will have to eat more if you want to gain lean muscle, especially protein. There are many other facets to gaining lean mass, but these are a few of the basics.
good luck