If it came with McAfee Live Safe, uninstall that.
If it has less than 8G of RAM and a spinning hard drive, upgrade to 8 G and an SSD.
What applications are running on the system? This is a very low-end budget system - it may not be suited to what you are running on it.
Without knowing much about your specs in that particular model. I can only recommend that you run Dell Update to make sure everything is up to date and Windows has also updated. If you bought this model with a base configuration such as with a Celeron CPU or possibly the Pentium Gold model. These CPU's are not the best choice except for basic tasks and limited multi tasking. They slow down easily due to their limited core counts. Its possibly that your expectations are exceeding the hardware that is in the model you purchased. Other possibilities are too many task running in background, a slow hard drive vs a SSD drive option and running too many processes for the amount of RAM in your device. CTRL-Alt-Del and access Task Manager can indicate what your system is doing if CPU is close or at 100% use all the time you'll need to find out what is using all that processing.