I was in a similar position and found the following quite useful:

- Leaverage your existing professional network to find your first client. Go above and beyond to ensure they see the value of what you offer.

- Build your portfolio and testimonial base from day one.

- A referal client is going to be alot easier to land than an organic lead.

- Develop your processes, standard operation procedures etc as soon as possible.

- Stick with your current job until it's just not possible to manage both / it's clear you have enough income to sustain yourself / you're confident in your business to the extent where you are comfortable living off some savings for a bit.

- Keep your costs low, don't subscribe to every saas. In saying that, don't try to save a few bucks by forgoing something you actually need. Rule of thumb is to sit on something for a week before committing to a new subscription. Audit your subscriptions on a monthly basis.

- Get something like Xero to make accounting easier, keep on top of your invoices, outgoings etc to make the accountants life easier / cheaper at the EOFY.

- Finding clients is a mixed bag. Depending on your target audience, happy clients might refer more clients your way.

- Bad clients are most likely going to refer more bad clients.

- Once you are taking off, a proposal software tool like Better Proposals is going to be very useful.

- Poor scoping / agreements will bite you in the ass in the long run.

- Allowing scope creep will set a precedent for all future conversations with a said client. Alot harder to walk it back once it's been said.

- If you agree to something out of scope, it's now your problem. Ie if it's not up to scratch, you can't come back and say well it was out of scope, we did our best.

- Having a "gap" in your quotes will help you with scope change conversations. Ie. Sure we can help you with that, but that will eat into your gap. A gap is an extra % charged upfront, that is deducted from the final invoice if unused.

- Go for something like Office 365 for Business for your emails etc. Explore all of its features. Most people don't even know the half of what a ~$8 subscription can get you. Emails. Cloud storage. Client booking systems (Like calendly but better). Teams. Automated forms.

- Setup your Google My Business to collect reviews.

- SEO for your website. Very important. Not too hard to get right if you are not in a competitive space. Write relevant blogs with long tail keywords your clients might be searching, especially if there isn't much competition on Google.

- Find clients who will have multiple projects for you. Whether it be an agency, or large client.

- Try locate avenues for monthly reoccurring revenue as soon as possible.

- Working 7 days a week for extended periods of time isn't going to do you any good.

- Don't buy your domain name until you have registered your legal business name. Make sure you you can try get the dot com + your local tld.

- Most client emails can wait until Monday. Don't set the expectation you're there 24/7.

- Don't get bogged down in a persuit for perfection. We are a web development agency and our website sucks, the rebuild keeps being pushed back because we get bogged down in client work. Our new rebuild is alot simpler and will be done way sooner.

- If this is your first time in business, try find a business mentor. Doesn't need to be in the same field as you, although that might help. Just someone who knows how to run a business

Either way, that's my 2 cents. Classic case of do as I say, not as I do. Alot of these have stemmed from my learnings running a web development agency for a few years. Good luck!