I would say that you are a baritone.

your songs are too short, but anyway you sound more a tenor to me than baritone. You also do too much "portamento" to my taste.

Of course your teacher is at the best position to evaluate your range. It is difficult to say just from a recorded song. If she says you are bass-baritone it is to be assumed she is right. You can try higher ranges if you prefer, working on it will improve your range but do this carefully and with teacher supervision, if possible.

If you are not going to sing lyric music (Opera), this division in ranges is not so important.

Modern popular music such as musicals are often written for voices that may extend from bass to tenor and so it exposes the singer to difficulties at both extremes. This is the case, for example, with The Phantom of the Opera (phantom role). Bari-tenors are probably the most suited for this genre, except for pieces written specifically for bass. Probably the composers general idea is that higher notes allow the singer to show off his/her capabilities and the public usually loves this range, being more brilliant and (normally) louder.

I would not care much about this for the moment and I would concentrate on mastering the right technique, such as not to sound "airy", having perfect intonation, voice shades and good projection and so many others.

The following is my personal opinion, but I believe that a good singer must be able to sing without mics and amplification and still be heard and be appreciated at least in a medium size hall. Many will disagree with this assessment so I insist this a personal view and the quality I would like to achieve for myself

Concerning portamento, it is a question of music style and taste. Too much of it can be irritating and point to a singer unsure of the right notes, adjusting them on the way. In some environments such as in choirs it is strictly forbidden

But it is not something to get rid off, just use it moderately and learn from professional singers when and how much to use.