Both translations are sentences, that no native speaker would use.
Ich gucke TV abends.
First thing to note is, that the verb »gucken« is not used in the complete German spoken Area. It is unusual in Austria, and - as I guess - also in Bavaria, but since I live in Austria I can't say much about the usage in different areas or Germany or Switzerland.
But even if you replace »gucken« by »sehen« (which is used by every German native Speaker) you get an unusual word order:
Ich sehe TV abends.
This is not really wrong, but bad style and very unusual. Better is this:
Ich sehe abends TV.
But even this can be improved, because I know nobody who says »Ich sehe TV«. People say »Ich sehe fern«:
Ich sehe abends fern.
While the google-version was unusual and therefor bad, but not absolutely wrong, the version from Yandex is definitely wrong.
Ich Fernsehen am Abend.
Verbs that are not the first word of a sentence must be written in all lowercase characters:
Ich fernsehen am Abend.
But here the verb stands in its infinitive form. It belongs to the subject (»ich«) and must therefore be declined so that is matches to 1st person singular:
Ich fernsehe am Abend.
So now we have two correct sentences(»Ich sehe abends fern.« and »Ich fernsehe am Abend.«), but they still differ in two items:
abends = am Abend
The word »abends« is a synonym of the phrase »am Abend«. Same is true for:
morgens = am Morgen
mittags = zu Mittag (be aware of »zu« instead of »am«)
donnerstags = am Donnerstag
There is a small difference: »Abends« tends to mean »every evening«, while »am Abend« tends more to be interpreted as »on one evening«. But this trend is weak and in most cases the context determines much stronger how this should be interpreted.
The second difference is this:
Ich sehe fern = Ich fernsehe
The verb fernsehen is a separable verb, so the version »Ich sehe fern« is correct without any doubt, but this doesn't mean that the other version is wrong. Many people use the second version, and also lots of people think it is wrong. This is one of the examples where one group says:
Rules describe how people use the language, and since there are many people who say »Ich fernsehe abends« the official rules that claim that this is wrong are outdated and must be replaced by new rules that allow this version.
The other group says:
Rules help you to learn a language. Follow the rules and your German will be correct. And since the official rules say that you have to split fernsehen, only the version »Ich sehe abends fern« is correct.
If you are a native speaker, you can decide which group you vote for. But if you are learning German as a foreign language, you better don't try to change the rules. You better follow the rules, because this keeps you on the safe side. So you better say one of this sentences:
Ich sehe abends fern.
Ich sehe am Abend fern.