Any Fitness expert here?

Straight one has more applications. Curved ones are more for specific movements in specific situations. So straight propably.

Empty barbell is enough in most exercises. Adding weight isn't difficult, so starting too light isn't really a thing.

 

K-I-S-S Keep it stupid-simple.
Get the straight barbell weighing 15 kg. It's called Ladies Olympic Barbell. It will be perfect for you.

 

Bodyweight training is different to weight training .

Let's say you are 140 lbs, I am 190 lbs and someone here is 240 lbs , who is going to be able (when fit) to do most push ups and pull ups ?
140lbs will, with weight is the opposite, when all fit, 240 lbs will move more weight .