Can you work out at the gym without lossing weight?

I literally only want to exercise to gain stregnth/muscle but most workouts I see geared towards women are almost always about towards weight-loss.(gotta love that). I actually am pretty content with thr size and shape of my body i just want to be healthier overall and be muscular enough to defend myself in scary situations.

i work hospitality alone (boss wont install saftey measures) and im not allowed to bring weapons to work so i need to be able to be strong enough to atleast knock out/stun a grown man. If anyone has any advixe let me know because lord everything i find is about "transforming you shape" or building a better ass. Give me a break lmao