There's many ways to improve on this. First of all, are u eating right, sleep enough, over-stressed etc. Things like that will affect your performance at the gym. The timing of your workout could also be one factor, but to me you can work on that over time. Some people just feel more energetic working in evenings compared to mornings vice versa but you can make it a habit so your body will adjust. You don't need supplement if you're just starting out technically speaking. If you're interested in gain muscles, firstly you should look at strength training and not cardio and make sure you're eating at a surplus to gain. I'm also a female and trust me, most females don't eat enough in a day hence why they get weak even after lifting a 5kg dumbell for 2 seconds.