Here are some ways to complete your sentences:

1/ I'm very sleepy after walk, I can't watch television.

"I'm so sleepy after my walk, I can't even keep my eyes open long enough to watch television." (Emphasizes the intensity of sleepiness)
"The walk knocked me out! I'm too tired to even think about staying awake for television." (Informal and lighthearted)
"Television sounds so tempting right now, but my eyelids are drooping and my body is begging for sleep. Guess I'll have to watch it tomorrow." (More descriptive and conveys the struggle between watching TV and resting)
2/ There were too many people in the stadium for us to get in.

"There were so many people in the stadium, it was like a human wall! No way we were getting through that." (Exaggerated tone)
"The stadium was packed to the rafters, not a single seat left. We had no chance of squeezing in." (Descriptive and uses figurative language)
"The crowd at the stadium was unbelievable, we got stuck outside and never even made it to the entrance." (Focuses on the overwhelming experience)
These are just a few options, and the best way to complete your sentences will depend on the tone you want to convey and the specific context of the situation.