I'm considering fillers... where should I start? Please give me some advice!

Lately, my face looks so haggard and I feel like I've lost weight in my cheeks, so I'm considering fillers. However, now that I'm actually looking into it, I'm confused because there are so many types and the pain and duration vary depending on the area.

In particular, I like a natural look, so my goal is to subtly enhance it without it being obvious.

I'm wondering which area is less intimidating to start with for someone getting fillers for the first time, and how much bruising or swelling usually occurs. Also, please let me know if there are any key points I absolutely must check when choosing a clinic! I'm a complete beginner with fillers, so I really don't know where to look first...