I'm going to go to the dentist (tomorrow), but I also need to improve my English in the morning, and I don't enough time to dohave much time for doing two things at the same timeonce. I'm going to go to the dentist (tomorrow), but I also need to improve my English in the morning, and I don't have much time for doing two things at once.

Adding "also" sounds a little more natural to me. You have to do one thing, but you *also* have to do another.

I'm going to go to the dentist but I need to improve my English in the morning and I don't have enough time to do two things at the same time. I'm going to go to the dentist but I need to improve my English in the morning and I don't have enough time to do two things at the same time.

I'm going to go to the dentist but I need to improve my English in the morning and I don't have enough time to do two things at the same timeonce. I'm going to go to the dentist but I need to improve my English in the morning and I don't have enough time to do two things at once.

aAlso, I will start a new course in business course. Also, I will start a new business course.

Alternatively: "Also, I'm starting a new business course soon."

also I will start new course inI'll also be starting a new business course. I'll also be starting a new business course.

I'm also I will start new course in businessstarting a business course, which will be difficult, I'm also starting a business course, which will be difficult,

iIt will be difficult, besides I willut I'm going to take a trip soon where I'll need to speak English . It will be difficult, but I'm going to take a trip soon where I'll need to speak English.

The "soon" isn't necessary, but it feels a little more natural to me. Although, if this is a trip which is actually a long time away, I might say something like "later". By "it will be difficult", you mean improving your English? You interrupted that subject with the topic of the business course, so to get back on track, I might use an "anyway" and then restate that topic: "Anyway, getting good at English will be difficult, but...".

iIt will be difficult besides I will, and what's more is that I'll be takeing a trip where I need to speak English . It will be difficult, and what's more is that I'll be taking a trip where I need to speak English.

"I'll be taking" sounds more natural You could say "besides that" but I don't think it quite fits here. "What's more" focuses on all the obligations piling up, "besides that" considers one thing separately from the others

it will be difficult besides I will takeand on top of this I'm going on a trip where I'll need to speak English . and on top of this I'm going on a trip where I'll need to speak English.

Do I sound natural ? Do I sound natural?