I want to record audio from my amp to my Computer/Phone, what application do I use, and how do I connect the amp to the PC? Do I use a wire or something? (Don't judge me, I'm not a technical guy, I just started playing guitar) (P.s. I don't have a mic for my pc)
While it is true how to connect the amp to your PC depends on what outputs your amp provides, it is most likely possible without a mic. Most current amps have at least a headset jack. Some with have additional outputs.
For me, I run a male mini plug stereo cable (like this one) from the amp headset jack to the input on my PC sound card. That being said, you will still need some software to record it.
It might be a little harder to record with your phone, but still achievable. Since you didn't specify, I will just offer this generic answer: you will need some type of adapter like this 1/8 to usb.
If you can update your post with your amp, and pc model and even your phone model, I can probably give you more concrete suggestions.
Most folks I know mic the amp and have the mic connected to an audio interface. Alternately, they don't use the amp but plug directly into the interface guitar input and then use software amps and fx. Others, like me, use a multifx unit which also has amp simulations and then connect to the line in on the interface or go directly into the pc via USB. Another way, depending on what type amp you have, is to run the output from your amp head through a loadbox instead of going to the speaker cabinet and from there to the line in of your interface.
For an android phone: Plug a 3mm male to male cord in the headphone out on the amp. Plug the other end of the male to male 3mm into the headphone side of a 3mm audio splitter. Open the recording software that comes with your phone. Plug in the male jack from the splitter (need a 3 ring male) into the phone. The recorder will say it will be using an external mic (it won't yet). Now plug the male you put into the headphone side of the audio splitter into the mic side. Now it will record the amps output. (If you plug into the mic side 1st it won't recognize it.)
Little odd but it works.
In my setup I have another splitter (both outputs the same) into my amp before the male to male above with the other side for head phones. (The headphones can't have a builtin mic.)