How to validate input fields and react-select if not using form tag?

I want the next button to only show up when the options are selected. One country and 5 cities. Also want to validate and input field that one is not enclosed in form tag. Please guide how can I validate the input field using hooks. Here is the code for react-select.

                        <Select
                          name="form-field-name"
                          onChange={this.handleChange1}
                          options={options1}
                          styles={Styles}
                          placeholder="Select country"
                          className="mb-3 Signup__right--select"
                        />
                      </div>
                      <div className="col-lg-7 col-md-12 col-sm-6 col-12">
                        <Select
                          isMulti
                          name="form-field-name"
                          value={this.state.selectedOption2.value}
                          onChange={this.handleChange2}
                          options={filteredOptions}
                          styles={Styles}
                          placeholder="Select city"
                          className="mb-3 Signup__right--select"
                        />
                      </div>```
This is the next button
```<div className="d-flex justify-content-start mt-2 mb-5">
                      <button className="Signup__right--button my-3 py-2 px-3">
                        <Link
                          to={`/candidate_step2`}
                          className="Signup__right--button--Link text-decoration-none"
                        >
                          Next
                          <img
                            src={arrow}
                            alt=""
                            className="Signup__right--button--img ms-2"
                          />
                        </Link>
                      </button>```


[This is how the interface looks][1]


  [1]: https://i.stack.imgur.com/povwt.png