Please check my sentence if it sounds ok and understandable.

This food, I think, will last me for at least a week or two.

....would sound better to a native speaker.

Im, I'd have omitted the "at least" as it seems somehow implied

Also Im, we often write "…will I think…" tho our collo includes "I think these…"

Thank you.

BY the way, can you please check me a couple more sentences?

- I have ability to last up to 5 minutes under water.

- I can outlast 5 minutes under water.

- I can last at least for 5 minutes under water.

How do my sentences above sound to the native English speaker?

None of your sentences sound "native". Try...

I have the ability to stay* under water for at least five minutes.

* alternatives remain/hold my breath but NOT "last".

- I have (an or the) ability to last (survive) up to 5 minutes under water (submerged)

Or, I can last...

- I can outlast 5 minutes under water. Not collo

- I can last at least for (for at least) 5 minutes under water


Also agree w Fres above