A/C or climate control

I have the car listed above XL model, and when I turn the knobs to make the air either hot or cold it doesn't seem like it actually locks in or stays at the temperature being cold now. It has been 100 degrees out lately, but it does have a minor ticking noise it seems. Today the passenger side was blowing cold and the driver's side air was hot and did do recharge few days ago. I ordered a blend door actuator from a parts store. But I'm not sure if I need both sides now that they are both blowing hot again. Or. If it's just the driver's side. But I need help also locating the blend door actuator for this year's make and model too. Is it a big pain and hard job to do? Or is it not to bad? If I can do it on my own. I'd rather. Do it. Help please. Thanks