Oral English can't be learned well in one summer vacation. You can do some extra basic work. English is a long-term language learning process. It is impossible to make rapid progress or once and for all. There may be a language genius, but I haven't seen it. In fact, it's a little late for you to think of practicing oral English when you get to college, because many habits (including pronunciation) may be difficult to completely correct (it's not impossible if you are really determined). I am actually a rural child, but I am lucky to avoid the road of dumb English, because I benefited from the enlightenment of a senior sister in Fudan in junior high school. If you really want to learn communicative English well now, you must work hard.
The new concept is a good material, which can not only be used to practice oral English. But since you don't have a good oral English foundation, you'd better buy a relatively basic oral pronunciation textbook, practice the basic pronunciation accurately, understand the rules basically, and then train a lot of language materials. I personally recommend Thomson's book, which sells well in America. You should be able to find some on Amazon.
Spoken English is definitely more than practicing pronunciation. When you spend three or five months correcting your pronunciation, you will find that the key to oral English is your English level: vocabulary accumulation, grammar mastery and understanding of language materials. Therefore, we should have the consciousness of improving our English level in an all-round way, which is the way to fundamentally improve our spoken English and express our feelings in English.
If you can, make some friends in Europe and America. Direct communication with native speakers is the most useful, and you may also gain friendship. Cross-cultural feelings are rare, which is very helpful to broaden one's thinking and vision. As for the usual "cramming" training, it is suggested to use the listening series of treading on thin ice, so that basically every word can be understood. It must be difficult and impossible at first, but you must stick to it and adapt to the environment slowly. Adaptation is completely the realm of English thinking process. Don't be greedy in training, just chew it up. Then you can fully challenge. It is suggested to listen to CNN for one hour every other day (you can download it and hear different interpretations of domestic events-CNN is a completely independent radio station, unlike voa, without any political bias. Stick to it and there will be fundamental changes.
Everything depends on persistence. In recent years, domestic college students pay more and more attention to the cultivation of practical communicative competence, which is a very good phenomenon. I hope to join the army that can use English. You will experience that kind of beauty.
P.S. I graduated from HKUST, and now I'm wandering around Chicago, which should answer some of your doubts. Keep trying.