When I looked back at the entry I wrote yesterday, I realized that it contained an error., because I have two orchids, not one. When I looked back at the entry I wrote yesterday, I realized that it contained an error, because I have two orchids, not one.

Merging the next (incomplete) sentence with this one.

Because II actually have two orchid plants, not one orchid. I actually have two orchids, not one orchid.

The other one came to my home earlierbefore this one. The other one came to my home before this one.

I understand what you mean when you say "earlier", but it sounds like came to your house earlier in the day. So a small change to show a greater gap in time between the arrival of the first and the second orchid.

The other one came to my home earlier. The other one came to my home earlier.

You could also say it “had come” to your home earlier, but the original wording seems fine to me.

And tThe flowers are bigger. The flowers are bigger.

I didn't mention it before, maybe. Perhaps it was because I was a little bit disappointed when I received it. I didn't mention it before. Perhaps it was because I was a little bit disappointed when I received it.

However, I (later?) found it was trying its best to grow and bloom. However, I (later?) found it was trying its best to grow and bloom.

Adding “later” would indicate you didn’t find/discover/realize this at the same time as what you found in the previous sentence.

Then I think I need toought I should respect it just like other plants in my little garden. Then I thought I should respect it just like other plants in my little garden.

Changed "think" to "thought" to be consistent with the tense you used in "I found it was trying" in the previous sentence. Changed "need" to "should" as it gives the notion that your conscience is telling you to do the right thing, instead of a mandatory task.

Then I thought I needed | Therefore, I think I need to respect it just like the other plants in my little garden. Then I thought I needed | Therefore, I think I need to respect it just like the other plants in my little garden.

Then, I think I need to respect it just like other plants in my little garden. Then, I think I need to respect it just like other plants in my little garden.

So I'm sorry toI ignored it when I wrote the entry last night. So I'm sorry I ignored it when I wrote the entry last night.

Small past tense correction.

So I'm sorry {to have ignored | I ignored} it when I wrote the entry last night. So I'm sorry {to have ignored | I ignored} it when I wrote the entry last night.