I guess you can file a trademark application yourself, which will cost a bit over $200 in government fees (for a long-term cost analysis, see https://www.ipfever.com/how-much-does-a-trademark-registration-cost/ ).
Here, the worst case scenario is you get a rejection letter (called Office Action). If there’s a mistake, you can amend it. In other cases, you can probably go around the problems. These will cost extra time and fees, but still you save money by not paying service/attorney fees.

Or you can use an online service, adding extra service fees (like $69 seen on today’s Google Search ads) to the calculation.
Here, you will likely save a good amount of time, and the process will be much enjoyable than filling out the government-designed application. Yup, it’s fine printed and for online versions, you will meet the old internet. Long story short, I think any help is better than no help.
Don’t expect a legal guidance though. You can hope the computer will one day replace the attorneys; it’s not today guys. There are other reasons, too. For example, the service would constitute an Unauthorized Practice of Law if it renders a legal advice without a license.

Alternatively, you can find a licensed attorney and pay much more.
Well, you saw this coming, right? An attorney defending the merit of legal counsel! Don’t worry. That’s not the point. I totally believe that you can DIY. The problem is that you will never know if you’re doing it right.
Starting from “Is my name/logo/mark trademarkable?” to “What’s the best way to protect my business interest?,” all entrepreneurs come across questions regarding trademark. However, lawyers typically don’t like answering piecemeal questions.
Thankfully, IPfever is where you can ask questions and seek help from attorneys; you do everything you can do yourself and leave only the rest to the attorneys.

You can request a free consultation. Also, you can simply choose to browse through articles from how to file a trademark application to basics to learn even when you don’t have your trademark yet or haven’t started your business.