I have an apex trigger which does not align (AT ALL!) with Salesforce "Best Practice" of never having queries and/or DMLs inside a 'for' loop.

I know this theory but, as I am new to coding, I need to break the ice and put this theory into practice (for the first time of my life) and I would like to ask if there is a "Best approach" to doing precisely that (moving SOQL-queries and/or DMLs outside the 'for' loop on 'Trigger.new', or for that matter, to move them from any loop).

Is there any approach, guide, video that could teach me to learn this "optimization process" of my code?

Below, here is my trigger (but please, do not give me the whole solution yet/inmediately, I am looking for a guide for me to try putting it into practice); thank you!:

==>This trigger adds Team Members to an Opportunity upon creation of that new Opportunity:

trigger OwnerManager on Opportunity (after insert) {
    for(Opportunity opp : Trigger.new){
        //Get opp Owner.Manager info
        Opportunity oppWithManagerInfo = [SELECT Id,
                                          Owner.ManagerId
                                          FROM Opportunity
                                          WHERE Id = :opp.Id];
        //Get opp Owner direct dependents
        List<user> directDependents = [SELECT Id
                                       FROM user
                                       WHERE ManagerId = :opp.OwnerId
                                       LIMIT 1];
        //Create Opportunity Team Role
        if (oppWithManagerInfo.Owner.ManagerId != null) {
            OpportunityTeamMember otm = new OpportunityTeamMember();
            otm.UserId                = oppWithManagerInfo.Owner.ManagerId;
            otm.OpportunityId         = opp.Id;
            otm.TeamMemberRole        = 'Sales Manager';
            insert otm;
            //Create another Opportunity Team Role with directDependent
            if (directDependents.size()>0){
                OpportunityTeamMember otm2 = new OpportunityTeamMember();
                otm2.UserId                = directDependents[0].Id;
                otm2.OpportunityId         = opp.Id;
                otm2.TeamMemberRole        = 'Sales Rep.';
                insert otm2;
            }
        }
    }
}