Can I apply for a Soft DTV visa now and still travel to Thailand in October?

Same questions every day

What’s your problem

This is a scam for sure

Depends on the embassy you apply through. Some advise not to apply unless your travel is within 90 days, and may reject an application if you ignore that. Given that it doesn't take terribly long for them to process the application, it's best to apply within that 90 days before travel. You can always book your travel, but be aware that if you are rejected, you'll need either a visa-waiver or a visa to enter Thailand, and may need to show return/onward travel within the validity of the waiver or visa.

No you need to learn how to spell Thailand correctly first then you can apply Thai visa

If you apply more than 3 months before the travel dates you provide they are unlikely to process your application or even reject it. But given it's a 5 year visa you can just provide dates no more than 90 days out