Why not start with talking to your company. This is standard legalese that says your employer owns anything you create whilst employed by them. As you have not yet started on anything it would be a good time to talk to them about getting this clarified. Don't rely on them verbally confirming that "we would never enforce this".

You can at least see if they are agreeable to changing it in principal before you bring in a lawyer. If you are to rewrite the clause then you need a lawyer.

If the company says "that's the clause you signed and we will enforce" you save yourself the hassle of dealing with a lawyer and can make decisions about whether you stay in that employment or if you look elsewhere and negotiate that clause in your way into new employment.

It should be noted that unfair terms like this could be challenged on grounds of reasonablness, but that would definitely required lawyers and could be expensive, and the company could probably out spend you on this. Making any side project a huge drain on your resources and making it difficult to get investors/buyers.