英语课在八点半

The English lesson will start at 8:30.
或者
The English lesson starts at 8:30
两个句子是太不一样，你选一个吧
一个是将来进行时，另一个是一般现在时

The English lesson /class begins at 8:30.

It is the English class at half past eight

The English lesson starts at 8:30 am。