Q: How can I produce a beat with Pro Tools?
Hmm, looks like you want to produce your own beats, rather than steal someone else's like a lot of people do!
OK, here's how you can do it (with any DAW, not just Pro Tools)...
First you need a collection of individual drum sounds. It doesn't hurt to mimic a traditional drum kit and use kick, snare, hihat and tom sounds.
You could record them yourself. Get yourself close to a drum set and record a few hits of each drum and cymbal. Choose the best.
Or you could sample them from existing recordings. Find a section of the music where the drums are isolated and record a few bars. Next, separate out individual drum hits using your DAW's editing tools. Cut very close to the beginning of each sound. If you like you can fade the ends, or leave them rough for a 'dirtier' feel.
Note that if you sample from copyright recordings, you will need copyright clearance before you can release your work.
When you're starting out, it's good to choose your tempo before you start assembling your beat. If you don't know how to choose, set the same tempo as an existing recording that you like.
(You can measure tempo by counting beats for a minute. Tempo is measured in beats per minute.)
Next, set your DAW to 'grid' or 'snap' mode. You will have the option to set the grid to sixteenth notes, eighth notes or quarter notes (and others). Choose eighth notes for now as this is the most practical setting.
Create individual empty tracks for each drum sound. Set your DAW to loop playback over a two-bar section.
Now, drag your drum hits to the new tracks at appropriate locations in the two-bar section. Where you put them is up to you, but if you are just starting out it's easy to put the kick drum sounds on odd-numbered beats, snares on even. Work the rest around that.
Once you have a rhythmic sound coming out of your speakers, you can experiment with moving around the individual drum hits to your heart's content. When you are happy, bounce your beat to a stereo file that you can use later in a song.
Of course, I have described only the basics. But when you have the hang of working with beats in this way, you can learn additional techniques as you go.