PROBLEM WITH DRUMS

Welcome to the forum.
You can enter MIDI data (notes) with your mouse in either the piano Roll view (PRV) or Staff view.
You then send that MIDI data to a hardware synthesizer or software synthesizer to hear it. If you're using your stock computer sound card, the MIDI synthesizer is the Microsoft GS Wavetable synth. I don't know what software synths come with SONAR LE, so I can't tell you which one to try; you'll have to tell us what you have listed under 'Insert Soft Synths'.
Here's what you can do with the MS GS Wavetable synth:
Select MIDI track 10. Ensure that the output channel is Channel 10 MIDI Drums. Open that track's PRV.
Click the 1/4 note icon above the PRV in older LE programs, or click the Event Duration button at the top in newer LEs based on SONAR X1, then select 1/4 note.
Click the drop-down arrow next to the Snap-to grid (looks like a grid) above the PRV (older programs) or right-click the Snap-to grid at the top (newer programs) and choose 1/4 note.
If it's set up correctly, you should have drum names on the left from top to bottom. Clicking the names should let you hear the drums.
Select the Draw tool (older programs) above the PRV or the Draw tool at the top (newer programs).
Draw a 1/4 note on the first and third beat of the measure on the bass drum line.
Draw a 1/4 note on the second and fourth beat of the measure on the snare line.
Draw a 1/4 note on all 4 beats on the high hat line.
Now go back to the Track view
The notes you just drew should be a clip. Right-click the clip and choose 'Groove Clip Looping'. The clip's corners should become bevelled, indicating that the clip is now a Groove Clip. Drag the right edge out as far as you like and the clip will repeat as far as you drag it. For newer programs, you will have to select the Smart Tool at the top to drag it out.
You now have a simple, steady beat to play or record to. Adding fills and other drummer stuff will come with time and practice.
There may be pre-made, ready to go MIDI clips included with your program that you can just drag into the tracks where you want them. Open the Loop Explorer and investigate.
Later you'll want to get an audio interface designed for recording and some drum soft synths for better-sounding drums. Some of those even create the drum tracks for you.
Good luck!

Good, SI Drums is a good place to start.
To put the MIDI clips in the correct position, set the Snap-to resolution to Measure, assuming you want them to start at the beginning of the measure.

What is the output of the MIDI track you're dropping the clips into? (per Beagle in the SHS forum)
If you have the snap-to resolution set to Measure and it's on (highlighted) it will place the clip at the start of the nearest measure to where you drag it. It's not doing that for you?

Welcome to the forum.
Are the notes in the correct place but the sound of the notes are off beat?
What soft synth are you using?
What is your sound card?