A lot of women lack that chest and upper body strength that guys initially have and that is often exposed in paddling.
If you are light then a longboard shouldn't be a problem , but you need to be forward enough that the nose is at the most about 1 1/2 iches out of the water no more and the board will then glide more easily. Try some still water paddling so you find the best position from which to paddle.
If you have the nose more out of the water you are trying to push the board through the water like a snow plow or bulldozer , it just doesn't work.
Another thing new paddlers do is flip their arms wide pull your paddle strokes right alongside the board from as far forward as you can reach and back as far as you can comfortably go.
Make your strokes firm hard and moderately fast (demented windmill thrashing doesn't work), you will gain strength and power the more paddling you do.
You will find a little further along your learning curve the difference between catching a whitewater wave and a green wave, ( next challenge) and for that you will need to be a more competent paddler, just go out and paddle around don't be afraid of little wipeouts or stuff like that just give it a go
I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun!