There is no clearer way I can say it: HECK NO!
A high-risk strategy like paid ads is the last thing you want to do when starting to market for the first time. Al ot of things have to go right for this to work; the ad targeting, timing, ad format, etc.
Pick a low-risk marketing strategy, like gathering up names of past contacts, unsold prospects, CPAs and attorneys from past transactions, prospects you never followed up with, etc., and inviting them for coffee or lunch and/or send them referrals. Simpler, higher chance at success.
Another low-risk strategy is starting a creative email newsletter. Send to clients and prospects every month and follow up with who reads it.
Don't go out and hire a marketing agency or ask them to tell you how to get started because that is like asking the barber if you need a haircut. They will take advantage of you and propose a grandiose bocu bucks offering full of high-risk stuff like Facebook advertising. YIKES!
Start small and low risk (no expensive advertising!!!) in the beginning; you can always ramp up later once you figure out what works. | 
