I watched the video from ceothe CEO of "Neiry" where Aleksandr Panov answered on questions.

"CEO" is an initialism (i.e. each letter stands for an entire word on its own), so it's usually capitalised

V(It was a) very interesteding video, where I found out details about neuro pigeons and about the future which is cato come.

"Interested" is used for the person experiencing interest. You could say you were a very interested viewer of the video.
"Interesting" is used for the thing causing interest. You can say the video is interesting.

In casual speech you can omit the "It was a" at the start, but in writing it's more natural to form a complete sentence.

To be honest, I dont know what I want to tellalk about.

"tell" is used when you're focusing on the recipient. Like "tell _you_ about". Since you don't mention the recipient, it's better to just use talk.

For example I signarranged toa meeting on Tuesday with a psychologicst yesterday, this will be my first session, and I have a lot of questions about me, my mental health.

Guessing what you mean by "signed to" here.

Because I figured out that I don't need any money whenever I feel bad myself.

I went to an arboretum for 200 rubles in a nearby district yesterday with my friend.

V(I learned) a very interesteding thing was about poison plants.

"a very interesting thing about poison plants" is just a subject on its own, it's not a complete sentence.

I was more funnierenjoyed it more than in the past week, because I decided that my last weekends in this year would be without many schedule, but unfortunately I also even feel tired.

I watched the video from ceothe CEO of "Neiry" where Aleksandr Panov answered onsome questions.

VIt was a very interesteding video, where I found outand I learned details about neuro pigeons and about future which is camethe coming future.

To be honest, I don't know what I want to tellalk about.

For example, yesterday I signed toup for a meeting on Tuesday with a psychologic yesterday, tst. This will be my first session, and I have a lot of questions about me, and my mental health.

BIt's because I figured out that I don't need anyto spend money whenever I feel bad for myself.

I don't understand the meaning here

I went to an arboretum for 200 rubles in a near district yesterday with my friend.

I saw a lot of fazans, squirrels, and other animals of surrounding plains.

what are fazans? do you mean pheasants?

VOne very interesteding thing was aboutere the poison plants.

I washad more funnier than in the past week, because I decided that my last weekends in this year would be without the stress of my schedule, but unfortunately, I also evenstill feelt tired.

I watched the video from ceoCEO of "Neiry" where Aleksandr Panov answered on questions.

CEO stands for Chief Executive Officer, so as an acronym the letters need to be capitalised, eg. the UN (the United Nations).

No need for "on", but you could say "answered some questions".

VIt was a very interesteding video, where I found out details about neuro pigeons and about future which is cato come.

It is best to start a sentence with something to introduce the topic, eg. "it was", "I found it", "I thought it was"

Came is past tense.

To be honest, I dont know what I want to tell about.

For example yesterday I signed to meeting on Tuesday with a psychologic yesterday, tst on Tuesday. This will be my first session, and I have a lot of questions about me, and my mental health.

Because I figured out that I don't need any money whenever I feel bad about myself.

If you mean you are feeling bad about yourself, as in you have low self esteem.

If you just mean you just feel sad in general, or about things happening in your life or the news, you would just say: "whenever I feel sad.

I went to an arboretum for 200 rubles in a nearby district yesterday with my friend.

Don't forget the articles in English.

I saw a lot of fazans, squirels and other animals of the surrounding plains.

You could also say: of the surrounding area, if you mean you saw animals native to the region you live in.

VeryThe most interested thing was aboutere the poison plants.

OR: " I was very interested in the poison plants."

I was more funnierenergetic than in the past week, because I decided that my last weekends in this year would be without my schedule, but unfortunately I also even feel tired.

OR: I was in better spirits than in the past week
OR: I was happier than in the past week