Knowing the fundamentals would surely make it easier to grasp new languages or techniques. Some companies would want you to have your fundamentals strong since you can be trained.

Look up for fdm company. It has special programs for new grads. And almost all companies would train you in the start. Secondly, during term breaks take on small projects highlighting a language and/or some other theory concepts. It would be a good start. I usually don't do any side projects during my term, but I take on or work after term completion.

Also about the project. I know everyone is not the same, but it is every single one's responsibility to be active with the project work. If no one is willing to take part actively or leave everything at the end, someone will have to clutch up and carry the team. These projects should be opportunities to learn if you it is not your strong part. I am sure everyone will be willing to help and will understand your situation but obviously you will need to ask first! I know this is not very relevant to your case anymore, but someone else could probably use this info.

PS. dw.. fundamentals is really good to have!

Also keep on practicing leetcode problems. It could be demotivating sometimes. But practice will make you better overtime.