Can I fix battery and change port on my 2017 MacBook Pro?

If it is the non-Touchbar model, then forget it. I will never do another battery replacement on the non-touchbar MBPro 2017 model. Even the Touchbar model is a pain.....I think most instructions have you remove the Logic Boar d and Trackpad which is a lot of work and not for those who are not used to working with the newer electronics because there are lots of extremely fragile easily damaged cables & connectors. The MBPro 15" (2015) model @Grant mentioned is a piece of cake compared to the USB-C Macs.

The 2016-2019 USB-C Intel Mac laptops have other things to consider as well. Are all the keys working properly? Those keyboards have an extremely high rate of failure. I'm well experienced with these laptops & I still get burned. In fact I have replaced the batteries in several of them only to discover afterwards that one of the keys had failed (I had tested the keys prior to the battery replacement) and another had the Touchbar fail. Various models also have other known issue and even some issues only experienced techs know about.

By having Apple replace the Battery....you will also get a new Top Case/Keyboard/Palmrest Assembly. The Apple OEM batteries are very good while third party Lithium Batteries are extremely poor quality even when purchased from a reputable vendor.

However, I really don't recommend spending any money on any of the Intel Macs for multiple reasons (a battery replacement is a borderline case assuming everything else with the laptop is perfect....most likely there are issues you just haven't noticed yet). The money spent on repairs is better put towards a new laptop especially since those 2017 models have so many issues and are 8 years old.

Battery, yes. Not simple, though.

https://eshop.macsales.com/shop/Apple/Laptop/Batteries?srsltid=AfmBOoqmBidIalUaqZRwzBYcLEMoEoRYW9QUz1gW23srpL8t-oEsaL7B

The charging port is really not a DIY thing.

Mac Repair and Service - Apple Support (your Mac is at least vintage and might not be serviced, depending on the actual model it may be obsolete and will not be serviced by Apple).

I bought one of those battery replacement kits, thinking it would be a straightforward replacement job on a 15-in 2015 model, where Apple battery service is no longer available.

I was a little surprised when safety glasses, rubber gloves, and several scrapers, and tube of liquid with multiple safety warnings were included in the kit. The glued-in battery required that noxious flammable adhesive-remover be applied, and the instructions stated that EVERY component in the chassis must be removed, to get it out of the way of the adhesive remover.

A closer reading of the VERY long directions for doing this, suggested that adhesive remover was a misnomer, and that adhesive-softener was more accurate.

This job was a rite of passage.

Punchline:

On any computer where Apple battery service is still available, my personal recommendation would be to pay the about US$250 and get THEM to do the job. They will replace the battery, trackpad, keyboard, and top-plate assembly in the store or depot. (The refurbishment of the old assembly is sent to a factory to be done under controlled conditions.)

A 90 day warranty on the repair is included, and typically, if it lasts 90 days, it is likely to last much longer.