By the rules, I know should be "sabo". It is sé, spelled s-e, and it is very irregular. Every other form of saber is regular.
Because sé on its own is a bit short, you often hear lo sé, literally I know it, rather than a bare sé.
No sé · No sé qué quiere · Quiero saber qué tiene
You must feel comfortable with two English words becoming one: I don't know what he wants is no sé qué quiere, with no separate word for he at all.
These have been held back on purpose so you would rely on the verb. The verb already contains the person, so these are added for emphasis, to clarify who you mean, or to draw a contrast.
Do not confuse these with the object words: lo is him, not he, and la is her, not she.
Position is flexible: no sé qué él quiere and no sé qué quiere él are both fine, one sounding more emphatic than the other. That distinction is much better picked up in live practice, because the emphasis is not only in the sentence but in the hands, the facial expression and the tone of voice.
Ella ve · Yo no quiero invitarlo, pero ella sí
You will do this naturally once you are practising, because your native language does the same thing. English always puts the she in, but you still stress it with your voice: "I don't want to invite him, but SHE does." That stress carries over by itself, as positive language transfer.
Ella is spelled e-l-l-a. A double l in Spanish is pronounced like /y/.
Add que to tengo and the meaning shifts from plain possession to have to, in the sense of must.
tengo (I have) + que → tengo que (I have to)
Que is what or that, and there is no comfortable translation for it in this use. Just take it that adding que gives you the have to meaning.
Tengo que hacerlo / Lo tengo que hacer · Tengo que verla / La tengo que ver · Tengo que comer ahora · Supongo que sí (I suppose so, literally I suppose that yes)
The -go pops up only in the "I" version. Every other person is built normally, and you can generalise the pattern to related verbs.
Salir is a verb of movement, so it takes the connecting a: salgo a comer, I am going out to eat.
Lo tengo · Los tengo · Lo obtengo (I get it) · ¿Cuándo vienes? · ¿Cuándo vienes a comer?
Cuándo is when. Do not let the English are you coming confuse you: there is a lot going on in that English which Spanish does not need.
Poner is to put, and like tener it hides inside English verbs. Wherever English has -pose, Spanish has poner.
Generalise the irregularity and suponer gives supongo, oponer gives opongo.
Lo opongo · Supongo
A recap of the useful verbs that take a "to" form straight after them: