The first book of the prophets, Yehoshua, begins with God commanding Joshua to battle the various nations in Israel.
Did these nations do any evil to the Jews prior? Or, was this simply the will of God?
Was there no other peaceful option for the Jews to obtain the land?
Jews are obligated to attempt to make peace with any peoples they come against. We must offer the nation the option of accepting the Seven Noahide laws and being subject to a tax and subservience to us. Violent action is only taken if this treaty is not accepted. In most cases, all adult males are killed, while women and children are spared. Exceptions to this rule are The Seven Canaanite nations1 and Amalek2. If these two categories of people will not accept peace terms, they are to be completely wiped out.
Joshua sent three letters to the nations before entering Israel3. The first gave the option to flee. The second gave the option to accept peace terms. The third gave the option to fight, (a final warning of sorts). Other than the Girgashites who left4, and the Gibeonites who treated, no cities made peace with Israel. It was the will of Gd that they be destroyed5.
1. General laws of war, Seven Cananite nations: Deut 20:10-20, Rambam Hil' Melachim 6:1-4.
2. Amalek: Deut 25:17-19, Rambam Hil' Melachim 6:6
3. Letters sent: Jeru Talmud Sheviit ch.6, Rambam Hil' Melachim 6:5
4. Girgashites: Lev. Rabah Metzorah 17:6
5. Refusal of peace other than Gibeonites, divine will: Josh 11:19-20, Rambam Hil' Melachim 6:4-5, Lev 18:24-28
In Addition to the answer here which is all correct.
Regarding your first question, about if the Canaanites did anything evil to the Jews prior. No they did not.
Regarding your second question about it simply being the will of Gd. Yes it was the will of Gd, No, it was not "simple".
In the book of Bereshit (Genesis) Abraham tells his children not to marry the people of Cannan. Even though he left his home, his father, and his country because of their idolatry , (as seen in Lavan's House); Abraham still preferred that his children and grandchildren marry someone from his old home, rather than marry a Canaanite.
It appears based on various verses of the Torah, that the Cannanites were involved in morally repugnant practices that so infused the land and culture, that the strictest rules were placed around our possibly being influenced by them.
Some of the repugnant behavior that they engaged in included being inhospitable to guests, lacking kindness, child sacrifices, body mutilation, and extreme superstition beyond the norm for a society.
This was a societal problem, not just some individuals, as the Tanach shows us, some individuals went against the trend of the society.
Throughout Tanach, we see that the Mercy that Israel had against the inhabitants of Cannan, became the cause of many problems for the Jewish people because they followed in the ways of the Cannanites, even after the Beit Hamikdash was destroyed, close to 1,000 years later.
