Knowledge of using tools is always beneficial, but it's not essential. Experience will enable you to make smarter choices when tackling problems or designing things though. For instance, building in enough space to use an Allen key to tighten something or having some insight into how much metal is enough to support something (you will calculate it, but with experience you will know if it's a reliable calculation).
I did absolutely zero work on vehicles before mechanical engineering. I did do a GCSE and A-level in design technology and an A-level in electronics though. However it is apparent who knows how to use hand tools and who doesn't. If you can get some experience, it will be perfect. If you can't, it's not the end of the world. You are not training to become a mechanic, you're studying as an engineer (and they have totally different strategies and solutions).