Victoria, I've made some modifications to your work in brackets in the text itself. As with your other piece of writing, sequencing of information and use of link words needs to be worked on a bit. You also need to review past tense verbs and check on your accents, eg, "tenía". Further check gender agreement, eg, "experiencia... aburrida". In reference to your opening paragraph, the journey wouldn't have taken 20 minutes on foot and m'bike, so: "El viaje duraba 20 minutos en moto, pero a veces yo iba a pie."
Do read your work thoroughly on completion for small errors, such as your spelling of "trabajo" in line one, and "llevar" (llevar joyas).
Remember, "lectura" doesn't translate as "lecture", but rather "reading / text". Thus, "...bocadillo antes de regresar a clase".
Again, hope this is helpful.

Spanish Coursework - Work Experience

Hice mis practices de trabojo en una escuela para especial needs niños (niños de necesidades especiales).
Duraron quince dias. El viaje era corto, iba a pie o en moto. El viaje duraba veinte minutos.
Empezaba a las nueve y terminaba a las tres y media.
En los descansos tombada un café y la lectura. La hora de comer era de doce a una.,comía un bocadillo o comida rápida.
Tenia que llevar ropa comoda. No podia llever joyas.
En mi opinion la experiencia fue muy aburido pero un poco util (útil).
Aprendi cosas (tales como) cuidaar a los niños. No conoci personas interesantes y ("ni", not "y") chicos guapos. El ambiente era malo, sucio y ruidoso.
El trabajo era dificil y peligroso porque fui doler y rasguñado por niños.
Estaba disgustada porque no aprendi cosas nuevas.
Me gustó porque no tenía que ir al instituto.
(Entre) mis cualidades (es - delete) me llevo bien con el personal, sé trabar (check spelling) sola y soy ambiciosa.
En el futuro quiero estudiar comercio o medicina. Quidisaera (check spelling) ser médico o mujer de negocios. Me gustaría ser mujer de negocios
porque quien (check this) ganar mucho dinero y es emocionante.
En general era estresante y aburrido. (This information belongs above, following "...no tenía que ir al instituto, pero en general era...".)
Me llevaba bien con mis compañeros. Lo peor fue cuidar a los niños y no estaba (estar) con mis amigas.

There's a need here, Victoria, to join your ideas together more using link words, and take care with the sequencing of information too. Let's take your first sentences at 1 and 2 below to illustrate what I mean: "Me llamo VO y vivo en N que está bastante lejos del instituto. Salgo de casa a las 7:30 y tomo un autobús..." It's only logical that you leave the house first, then take the bus/train. Alternatively, by the same reasoning: "Tomo un autobús... instituto después de salir de casa a las 7:30."
"Asamblea" is feminine, so check your last sentence at 7 for gender agreement. Similarly, line two at 9 - "inglés" is masculine. And line one at 10.
Do you really want to say your teacher is 'useful'? "...ofrece ayuda", perhaps, or "es ayudoso". And since you use 'divertido' quite frequently, you might refer to your teacher as being simpático.
At 8, your upside down exclamation mark should precede pero: "...amable,¡pero grita mucho!"
"También leer". Don't you want to say you also like to read?
Also change: "... duraría 35 minutos".
In reference to days of the week in general, we use the plural form: "los lunes", here.
At 13, 'discipline' should be a noun when used with "hay", rather than a verb.
At 14, note the order of adjectives: "una falda larga de color azul oscuro".
Check for plural agreement at 16.
At 17, "...nos deben permitir llevar...".

Final observation, at 19, check for the missing accent in your use of the conditional.

I hope this has been of some use, Victoria. Keep the practice up. It's a fun language.

¡Suerte!

Victoria,

Good content, good subject and style, but you are making lots of grammatical errors. What you are doing is trying to translate word for word, or "thinking in English", instead of trying to put together sentences which may be a bit different but are correct Spanish ways of saying things.
Grade- D/E, but not far off a C.

Corrections:
All verbs should be in the 'tu' form, which is friendly, not 'usted', which is too formal for a pen-friend
line 1: sus not su los; habian not habia
line 2: tu (with accent) y tu familia sois
line3: mas que bienvenidos a acompanarnos = more than happy to join us
line 4: situada
line 5: has dicho not dice: ganas de not deseo
line 7: replace el with bastante para
lines 8-9: put verbs in 'tu' form
line 12: estoy not soy
line 13: como en Madrid
line 14: You can't say, "Is s/he into...."- you have to say "le interesa a tu mama o papa...?"
line 15: mucho not muchos
line 16: si visitas not sobre visitar
line 18: hermosa abajo is wrong; what are you trying to say?
line 21: su propia not sus los propios
line 22: puedas