Any difference shigotonisuru and shigotosuru?

Any difference 仕事にするand 仕事する?
I stumbled upon many times for different forms. But what I understand, they are literally the same thing arent they?

They mean the same, but I think there is a slight difference in nuance.
仕事に implies there are other options (like eat lunch), but you choose to work.

Can you give the whole sentences

仕事にする would be used when you want to talk about doing something "as occupation," or turning something into your profession.
絵を描くのは好きだが、仕事にするのはむずかしい。(I like painting pictures, but doing it as an occupation/as a profession is difficult.)

仕事（を）する can simply mean "to work."

仕事する　Direct translation is "make a work".
仕事にする　is " make to a work"

に　is used like "to" to imply the direction.

書くことを仕事にする
make writing to a work
書く仕事をする
make a work of writing

The verb " 仕事する " has a broad range of meanings,
though it’s not so broad as that of the verb "work" in English.

Usually " 仕事する " is used for persons.
Personally I use " 働く {はたらく} " more often,
which is closer to "work" in English.

仕事（を）する can simply mean "to work."

Also " 仕事 " as in " 仕事をする " may mean a (steady) job as occupation | profession.

"John はりんごを育てる仕事をしています。"
usually means
John does a job of cultivating apples,
i.e. John cultivates apples as his job,
almost the same as
"John は りんごを育てるのを仕事にしています。"
[John makes it a job to cultivate apples.]
and as
"John は りんご栽培 {さいばい} 農家 {のうか} です。"
[John is a farmer cultivating apples.] .

cf.
"John は果樹園 {かじゅえん} で仕事 (を) しています | 働いています 。"
: John may be a farmer managing the orchard, a part-timer or a seasonal labor.

I think the comments above answer properly the original question. However, as none of them mentions one ordinary use of “仕事にする(not 仕事をする), which is generally used in ordinary conversation, let me make a little additional comment.

As an independent expression (i.e. with no object), “shigoto ni suru” can mean “return to work after some break”, or less often, “begin to work (at a meeting for example) after some preliminary or greeting chat which has nothing to do with the work (i.e. the proper subject of the meeting) itself.

Japanese is a highly context-dependent language. You need to specify that.

If I just heard of 仕事にする or 仕事する, I remind of a serious situation. The former is used in a scene choosing a type of work, turning a hobby to be a profitable one. The latter for a situation starting to work after school graduation.

Neither would be yours, I guess. I think you mean 仕事にしようか? or 仕事しようか? at the time of a break at a working place. Both means "Let's go back to work." But, the settings of the speaker and the listeners should matter here. The former has a nuance that we don't like to do so. We are reluctant to go back to work, but we should do so. The speaker should have a higher or equal social stage than the listeners. If not, you would be scolded. The latter has a more neutral tone. But if the speaker is a boss and the situation is during working hours, you are just scolded implying "Don't be lazy." So, either phase is rather touchy, even you are a boss in your working place.