How do you get your first customers on a tight budget?

I'm assuming you're starting from scratch. If I was starting from scratch today, here's the advice I'd give myself:

• Get some revenue flowing by asking family and friends. Ask them for feedback - when you're starting out, you're not going to be as good as you will be with 3-5 years of experience, and that's ok as long as you're open to improving. Cost: $0
• Set up Jobber from day 1. Every city builds the roads before they build the houses-- Jobber is the infrastructure you'll need to rapidly grow. Cost: $40/month
• Offer your first 50 customers a promotional deal. You can set up referral codes using a Jobber plugin like LoyalAs. Cost: $25/month
• Build website using an affordable CMS like Wix, just buy the domain for a year (usually there are promos). Make the domain short and sweet and easy to spell. If you're not handy with this, you probably know someone who is. Bribe them with your services. I traded my dentist wisdom teeth extraction for ice chipping once. Cost: $16/month
• Create social media accounts for your business and showcase your work. Cost: $0
• Ask your first customers for a 5 star review on Google or social media. Only ask them if you felt like you definitely earned that 5 star review. 
• Set up email hosting. Getting contractor emails from @outlook.com or @gmail.com doesn't look as professional as @yourcompanyname.com. You'll need to make yourself look big and professional if you want to earn big and professional $$$. Not to mention, email hosting usually comes with office apps. We use Google Workspace. Cost: $10/month
• Start a basic Google Adwords campaign and target postal/zip codes near you rather than the whole city. A budget of $3-5 per day can do wonders. If you're working in a seasonal industry like lawn care, snow removal or Christmas lights, 2-4 weeks before you'll need to start work is the right time to advertise. Keep in mind that Google takes 3-7 days to start really delivering ads smoothly. Cost: $150/month
• Answer the phone in the first 2 rings. Emails within 6 hours. Texts within 1 hour. People who click on your ad are people who are actively seeking out your specialty. If you can't help them, they'll find someone who can. This may mean answering the phone from 6am to 11pm. If you're starting out, that's the kind of hustle you'll need. And answer your phone like a business: "Good Morning, this is Chris as Mow Town"  Cost: $0
• Practice and continually improve your pitch to see what techniques or phrasing gets sales. Cost: $0

Good luck, and work hard!