I am practicing 'even if' pattern with the following example sentences.

· Even if I wash my car, it still won’t look new.

· Even if I tell my parents the truth, they will be angry at me.

· Even if I had free time tomorrow, I wouldn’t want to go to the beach because it’s too cold outside!

I can't understand the 3rd one.
I think it should be "Even if I 'have' free time tomorrow, I 'will not' want to go to ~"
Can somebody explain why I should use 'past tense' in that sentence?

See a translation

Often in English we use "could" and "would" in present and future tense. Example: "Would you go to the store for me tomorrow?"

I can think of two reasons why we use "could" and "would" like this.

(Your question is 2.)

1. To make a request.

Along with "will you?" and "can you?", "would you?" and "could you?" are used to ask someone to do something. The meaning is the same.

2. To imply a reason/condition.

"Would" and "could" imply there is a reason why someone will or can do something. We use it all the time like this. Sometimes we don't even know the "reason" or "condition."

Imagine using "if" or "because" when using "would" and "could". Example:

"I would like to go to the beach tomorrow." (Because it is going to be nice weather.)
"I could help you move into a new house next week." (Because I have a truck.)
"I would buy a new phone." (If I had the money.)
"I could be a famous singer." (If I had the motivation.)

The sentences in the ( ) are examples of reasons. Unless a person explicitly says the reason why they're doing something, we can only guess. Sometimes, the reason is obvious, however.