You have taken the very first step wanting to provide services. Some quick tips that helped me.
1. Network on forums just like this one.
2. Submit services to all platforms to extract clients from those platforms such as F iverr, Up work, people b y the hour , the list goes on and on.
3. Know your service and who it is for , having a general service from my experince will net less profit , being specialized for a industry or niche will help you in the long run.
4. Once you know your target audience pick up the phone , this one is so over looked and has landed me 50% of my clients.
5. Referrals , referrals , referrals , get a name and a number from your clients or better yet get the introduction.
6. Upsell , selling a client more is easier than getting new clients.
7. Your last client was your best client , never forget .
8. Stay hungry
Best wishes hope this helps