non-solicitation

Courts tend to not like restrictions on people's right to earn a living--they acknowledge sometimes they are necessary, but tend to read or interpret them narrowly. According to what you describe, the limitation is just on taking clients, not on working for another agency. Therefore, you can work for another agency legally, but do not "solicit, divert," or take away" accounts. Instead, you will probably need to prospect for new accounts.

Where it gets a little grey is that if a client goes to you of their own free will without you soliciting them, that would seem to be ok, but proving there was no solicitation can be difficult. Generally speaking, if a client jumps ship with you right away, it looks like you took them; if they go to you after 6 months or more, it is more reasonable that they are not satisfied with the new person handling their account and want to work with you again. That's not a hard and fast rule, and this is a tricky area.

If 24 months is much longer than similar non-compete's in your industry, then you might also be ok with only honoring it for the usual or standard period--courts again don't like to see someone be deprived of their ability to make a living. But once more, this is tricky, since you'd be going against the plain language of what you signed.

This sounds like a case where you need advice from you own attorney, with whom you can confidentially share all the info about the terms of the contract, your salary, the expectations that a new employer would have for you bringing clients, what is generally done in the industry, etc. Look for someone who is not just an experienced employment law attorney who works on non-competes and similar clauses, but ideally has experience in/with your industry.