Do not use mixed grip - rather a hook grip. Let form dictate load.
Front squats should be performed to full rage - ass to the ground. If you can not go this deep then address these issues now before they become an issue.
Single Leg Romanian Deadlift
Single Leg Squats
If new to lifting then you should be looking at full body training 3 times per week starting with 2-3 sets of 9 for the first month.
Up you food intake - mostly meat & veges. Focus on as much natural food as possible - avoid grains and dairy.
Everyone has their own ideas when it comes to supplements, but start with the basics.
Fish oil - up to 10g per day
Greens - been promoted here lately but been around for decades - I use a combo but you could just go for one of the standard off the shelf products.
These are just the basics. There are more but you can read up more around here.
Read more info from this site to start - but take everything with a grain of salt.
Just remember to get the diet right first - the diet needs to be able to support the training.