For starters, congratulations on the weight-loss and beginning your journey! I definitely agree that a personal trainer would be ideal- Even if just for a few months to get you established on proper form on exercises as well as the importance of proper nutrition. Learning the basics is a huge part of getting started! You can watch videos, look up beginner workouts programs, etc on the bodybuilding website- but it’s much harder to learn that way(I learned that the hard way/over a couple of years) If I were you, I would ask people at your gym their opinions on the best trainer though- not all trainers are worth your time and money unfortunately. Start with learning the basic lifts(bench, squat, deadlift, shoulder press etc)...and please please don’t be afraid to push yourself to lift heavy as you gain strength! You will be amazed at the positive changes as you start gaining muscle!