They won't be able to do that. Militarily.
Russia has sea (of Azov) access and land access and Crimea access to re-supply those areas. Ukraine has no access except to attack them head on from the interior of Ukraine.
I predict they will be able to push Russian forces back across the Dnieper River (taking back Kherson Oblast) which would push them further away from Odessa and Russia's aim to take Odessa and create a land bridge all the way from the Donbas to Moldova (the Russian held Moldovan territory of Transdniestra). And that they may be able to take back some towns and territory in the Donbas and Zaporizhia regions.... from the direction of Kharkhiv southward, not from the coast inwards.
This doesn't affect Russia's current hold on a land bridge to Crimea. Russia holds this, they already have it, and will not let go of it, and I believe, will be able to maintain their hold on it.
The most the Ukrainians will be able to reconquer, in my opinion, is the Kherson Oblast and the inner fringes of Zaporizhia and the Donbas.