New to Gardening: Rhododendron help?

I bought my first house and the last people to own it never took care of the garden, the people before them were avid gardeners. I decided to take on weeding the garden and taking out some ugly, dead plants and it’s looking a whole lot nicer now. However, I am extremely new to gardening myself as I’ve never owned a place where I could have one.

I’m not 100% sure, but it looks like I have a couple Rhododendron bushes but one looks much less healthy than the other. I’m wondering if anyone can give me some insight here on how to make it happier, if it’s a total loss, or could point me to a place where I can get help.

Thanks!

Links: Healthier Rhodo https://m.imgur.com/OmomMnz

Other Rhodo https://m.imgur.com/3tOsbqR