Welding is not an easy thing to do. It takes lots of practice and education to do safe, strong welds. This is why it takes welding students many months of instruction and practice to become certified.
Since you have never welded, this is not the time to learn. Attempting to weld this bracket as your first welding experience is a very bad idea. You are very likely to damage your car and hurt yourself, and very unlikely to complete the repair.
Welding is a very useful skill and lots of fun, but you must do so safely. It's virtually impossible to learn how to weld purely by reading manuals and looking at videos. After some basic instruction, you need to practice on large pieces of scrap metal and have an experienced welder review your work and give you feedback/direction.
Great welding is like learning how to play a guitar. It looks very simple, and skilled welders make it look easy, but there is a lot of technique involved in preparing the surfaces, coming up with a repair strategy, and handling the welder.
I suggest you fix the bracket some other way ie have a mechanic do it. then take your time to learn how to weld properly. A course at a local technical college would be ideal.