It would still be challenging. Maybe Spivak is gentler, but the problem with Spivak is that their are virtually no applications.
Both are good, and it doesn't hurt to try.
If you read Book of Proofs, I read it, and I think it's a good book with challenging exercises, then you should be ready.
But when you say reading. Did try to prove why such and such is true. Do you understand the different proof methods. Relations? What does it mean to have an equivalence relation. Definition of a partition, equivalence classes. How the collection of all the equivalence classes forms a partition on a set.
What about the function chapter?
What a function is. Definition of image and inverse image etc.
Can you do most of the problems without looking at the solutions?
If yes.
Then a good first book in linear algebra would be Friedberg, Insel,Spence: Linear Algebra.
Axles is good. But it can be a little difficult if you are not used to proof theorem. Even if you can't fully understand it, I think it's worth having it on your bookshelf.
A nice book that is gentle but well written: Pinter: A book on Abstract Algebra. I'm reading this book for preparation for my algebra course. I like it. I also read his set theory book.
You can also try your hand at geometry. Kisselev Planimetry, Moise geometry. Good way to practice proof writing on things you seen before...