Hi Julia,
Welcome to our Group!! I resonate your concerns/worries about being nervous not bringing home a decent paycheck with benefits! I went full-time as of May and left a good paying job as well so far I have no regrets though. :)
To save on having to get a Merchant Account to accept payments from my clients, I bill all my clients using PayPal that is hooked up to a service I use called Freshbooks which allows me to track my time I spend on each client's projects as well as send them electronic invoices via email directly from my time logs. On the invoice there is the option you can use to include a link for your client to be brought to PayPal where they can pay you. You can even add your logo on your invoices!
It's simple and easy to use, looks professional to your client, and also allows you to keep track of expenses that you need to charge back to your clients. It also keeps track of who has paid you, who has not, and keeps a running total of amount invoiced and payments received over time.
Hope this helps!
Kind regards,
Linda...