The best thing to do is to have your geographic pastor (assuming you are currently attending your geographically assigned parish) address a letter to the pastor of your chosen parish that it’s OK for you to change parishes.
For example, this kind of process is required in the Archdiocese of Philadelphia. Parishioners in the AD of Philadelphia must receive the the Sacraments of Initiation in their home parishes. And one must have their canonical pastors permission to marry. So permission to officially change parishes must be official.
However, in some smaller parishes, they don’t enforce their canonical boundaries (or at least the parishes take care of the paperwork behind the scenes with no questions asked.)
Even if you don’t need the letter in your diocese, it’s good to have in case a future Bishop decides to enforce the canonical boundaries due to resource issues.
Now, if you are not worried about funerals, parish cemeteries, communion for “shut-ins”, visitation at hospitals, being elected or appointed to the pastoral committee or parish board of trustees, weddings, baptisms, first communions, and/or confirmations… just simply go to whatever parish you wish to attend. You can always attend mass and confession at any Catholic Church.
But the other sacraments and services are typically and canonically limited to geographic parishioners due to resource management. And because a pastor is responsible for ALL souls in his territorial (or personal) parish (even the non-Catholics), just like a Bishop is responsible for ALL souls in his diocese.
I pray that this is helpful.
God Bless!