eccentricanomaly
Revana_Blay
Listen, as a female you can't get "bulky" like a guy without anabolic steroids. It just doesn't happen. The reason guys bulk is because of their T levels. Look at female Natural physique competitors (I'm a fan of Sasha_Anne_Fit on instagram.) They don't wind up bulking despite the weights they lift. Sasha in particular goes insane on her workouts and drops to dangerous levels of BF% without losing an attractive physique.
My recommendation is to get on with a strength routine and adjusting your eating habits a little at a time. You'll eventually want to be doing macro control.
But seriously, don't be concerned about "overdoing it."
I mean overdoing it like pulling muscles or injuring myself.
Okay, that would make sense, too. I speak to women all the time who have the aforementioned concern as I've addressed it. In your case, I'd probably recommend a few sessions with a PT. Correct form will walk you miles in injury prevention. Considering you're "at home" (I'm assuming with the type of equipment you have) this may not be the most feasible option.
I subscribe to
these guys on Youtube. They have videos about correct form for the various exercises and if you have access to mirrors while you workout, you should be able to watch your own form. They have also started developing a series for creating a home gym, with everything from building your own bench to how to workout with the different types of equipment you might have.
The fact that you have very light weights is good and bad. You may want to invest in a plate weight set
something like this one that will let you progress as you get stronger. In the meantime, my recommendation would be towards callisthenic routines which you can add your small weights to. Getting definition in your upper body will definitely be done by heavier weight training, though. The good news is you can work on your form and get them right for when you start rolling on with the heavier weights.